I have completed the game in terms of weight, currently at 500 kgs(got the fat streamer ending and normal shower scene ending with Jamie).
I am also unable to enter the magical shop due to my weight. People in the comments below say to talk to the fairy. But the only options I get after I click on talk to fairy are the apple, cantaloupe, watermelon. No such things as 10 watermelons or anything that can help me pass through. I have also not been able to do any gothic events.