Slim7833:
They don't approve or want to help with the process cause of the cost and the card worried about my health but I want this and I want to gain up to 50lbs before December if possible
A few things:
1. December is in 4 months. You are a slim, 19-year-old. Typically, you will be fighting against your high metabolism. It is unlikely you will gain 50 lbs in that short of time. This isn't saying you can't gain at all. I'm saying you should adjust your expectations, or you will frustrate yourself.
2. You are an adult. I know that at 19, you still kinda feel like a child in some respects. But you are not. If you want to indulge in your fetish, you need to be responsible for it yourself.
All you can really do with your parents is establish boundaries and show them how you are taking care of yourself despite the weight gain. So eat a balanced diet and exercise.