Ограничение UNIQUE не выполнено или не выполнено ограничение NOT NULL - между ними нет

Question

Я работаю над проектом, в котором пользователь сначала регистрируется, затем заполняет две отдельные страницы информации о своем профиле (на страницах PII и finalPII). По какой-то причине я не смог правильно сохранить эту информацию в моей модели профиля и всегда получал одну из двух ошибок, связанных с идентификатором пользователя: либо ограничение UNIQUE не удалось, когда я включил строку profile.user = request.user, либо NOT NULL Ошибка ограничения связи, когда я избавляюсь от этой строки. Я не уверен, где находится середина, и я очень ценю любую помощь или совет, данный.

views.py

from django.shortcuts import render, redirect
from django.contrib import messages
from django.contrib.auth.decorators import login_required
from .forms import UserRegisterForm, UserUpdateForm, ProfileUpdateForm, PIIForm, FinalPIIForm
from .models import Profile




def register(request):
    if request.method == 'POST':
        form = UserRegisterForm(request.POST)
        if form.is_valid():
            form.save()
            username = form.cleaned_data.get('username')
            messages.success(request, f'Your account has been created! You are now able to log in')
            return redirect('login')
    else:
        form = UserRegisterForm()
    return render(request, 'users/register.html', {'form': form})


@login_required
def profile(request):
    if request.method == 'POST':
        u_form = UserUpdateForm(request.POST, instance=request.user)
        p_form = ProfileUpdateForm(request.POST,
                                   request.FILES,
                                   instance=request.user.profile)
        if u_form.is_valid() and p_form.is_valid():
            u_form.save()
            p_form.save()
            messages.success(request, f'Your account has been updated!')
            return redirect('profile')

    else:
        u_form = UserUpdateForm(instance=request.user)
        p_form = ProfileUpdateForm(instance=request.user.profile)

    context = {
        'u_form': u_form,
        'p_form': p_form
    }
    return render(request, 'users/profile.html', context)

def PII(request):
    if request.method == 'POST':
        form = PIIForm(request.POST,)
        if form.is_valid():
            #form.user = Profile.objects.get(user=request.user)
            #
            profile = form.save(False)
            profile.user = request.user
            profile.save()
            #
            #form.save()
            return redirect('FinalPII')
    else:
        form = PIIForm(request.POST)
    return render(request, 'users/pii.html', {'form':form})

def FinalPII(request):
    if request.method == 'POST':
        form = FinalPIIForm(request.POST)
        if form.is_valid():
            profile = form.save(False)
            profile.user = request.user
            profile.save()
            return redirect('/')
    else:
        form = FinalPIIForm(request.POST)

    return render(request, 'users/finalpii.html', {'form':form})

models.py

from django.db import models
from django.contrib.auth.models import User
from django.core.validators import RegexValidator
from django.db.models.signals import post_save
from django.dispatch import receiver
from PIL import Image
import birthday

class Profile(models.Model):
    GENS = (('m','Male'),('f','Female'),('o','Not Represented Above'))
    RACES = (('ai','American Indian or Alaska Native'),('as','Asian'),('bl','Black or African American'),('hi','Hispanic or Latino'),('ha','Native Hawaiian or Other Pacific Islander'),('wh','White'))
    ETHNICITIES = (('n','Not Hispanic or Latino'),('h','Hispanic or Latino'))
    INCBRACKET = (('a','$0 - $10,000'),('b','$10,001 - $40,000'),('c','$40,001 - $80,000'),('d','$80,001 - $150,000'),('e','$150,001 - $250,000'),('e','$250,001 - $500,000'),('e','$500,000+'))
    EDUCATION = (('NE','No Formal Education'),('HS','High School Diploma'),('AD','Associate Degree'),('BD','Bachelor\'s Degree'),('MD','Masters\'s Degree'),('DD','Doctorate'))
    EMPLOYMENT = (('e','Currently Employed'),('u','Currently Unemployed'))
    STATES = [('AL', 'Alabama'),('AK', 'Alaska'),('AZ', 'Arizona'),('AR', 'Arkansas'),('CA', 'California'),('CO', 'Colorado'),('CT', 'Connecticut'),('DE', 'Delaware'),('FL', 'Florida'),
    ('GA', 'Georgia'),('HI', 'Hawaii'),('ID', 'Idaho'),('IL', 'Illinois'),('IA', 'Iowa'),('KS', 'Kansas'),('KY', 'Kentucky'),('LA', 'Louisiana'),('ME', 'Maine'),
    ('MD', 'Maryland'),('MA', 'Massachusetts'),('MI', 'Michigan'),('MN', 'Minnesota'),('MS', 'Mississippi'),('MO', 'Missouri'),('MT', 'Montana'),('NE', 'Nebraska'),
    ('NV', 'Nevada'),('NH', 'New Hampshire'),('NJ', 'New Jersey'),('NM', 'New Mexico'),('NY', 'New York'),('NC', 'North Carolina'),('ND', 'North Dakota'),('OH', 'Ohio'),
    ('OK', 'Oklahoma'),('OR', 'Oregon'),('PA', 'Pennsylvania'),('RI', 'Rhode Island'),('SC', 'South Carolina'),('SD', 'South Dakota'),('TN', 'Tennessee'),('TX', 'Texas'),
    ('UT', 'Utah'),('VT', 'Vermont'),('VA', 'Virginia'),('WA', 'Washington'),('WV', 'West Virginia'),('WI', 'Wisconsin'),('WY', 'Wyoming')
    ]

    user = models.OneToOneField(User, on_delete=models.CASCADE, null=False, blank=True, default = '')
    image = models.ImageField(default='default.jpg', upload_to='profile_pics')
    gender = models.CharField(max_length = 1, choices = GENS, default = '')
    birthday = models.DateField(default = '1900-01-01')
    race = models.CharField(max_length = 2, choices = RACES, default = 'x')
    ethnicity = models.CharField(max_length = 1, choices = ETHNICITIES, default = 'x')
    income = models.CharField(max_length = 1, choices = INCBRACKET, default = 'x')
    education = models.CharField(max_length = 2, choices = EDUCATION, default = 'x')
    employment = models.CharField(max_length = 1, choices = EMPLOYMENT, default = 'x')
    street = models.CharField(max_length = 100,default = 'x')
    city = models.CharField(max_length = 50,default = 'x')
    state = models.CharField(max_length = 2,choices = STATES,default = 'x')
    zip = models.CharField(max_length = 10,default = 'x')


    def __str__(self):
        if self.user_id:
            return f'{self.user.username}'

    def save(self, *args, **kawrgs):
        super().save(*args, **kawrgs)
        img = Image.open(self.image.path)
        if img.height > 300 or img.width > 300:
            output_size = (300, 300)
            img.thumbnail(output_size)
            img.save(self.image.path)