I feel really bad for you and I'll try and offer some advice.
For one dont feel shame for what you do. I dont think sigmond freud ever delt with diaper lovers but I think he would think something about how we all have energy we need to release. Diaper wearing is a very safe and innocent alternative to say drugs, unprotected sex, or heavy drinking. Yeah its something most people dont do but your not hurting yourself or anyone else.
For now downplay your diaper interest as much as you can. Maybe go to the psyc and keep the conversation on other parts in your life. Perhaps start acting more cheerful then you used to. Just kind of put your diaper interest into hibernation for a while.
We are all willing to help you in anyway we can