I will come from a different angle..

I have Anorexia and have been in and outta remission all my life , I am now 48 and I have just recently been able to get my weight back up to a " healthy level"

Denying myself food is an eating disorder but its also a self harm, yes I have self harmed myself for years because I have a lot of baggage and self imagine and also that lovely bit called Self esteem.

If your just eating and eating you could easily be dealing with a eating disorder and its a form of punishment/self harm.

Yes most all psych meds do cause weight gain, There are ways of dealing with it through lifestyle changes .. Diet is a filthy word that needs to been done away with. Diets fail damn near every time, healthy eating by making life style changes will help you not gain weight but the healthy foods your eating even if your over eating them , its healthier than over eating junk foods.

If your okay with your weight .. then no need to change things , but your post reads of needing help , feeling lost, searching for acceptance, looking for something to grasps onto. I'm sorry your in some way hurting in such a way. Your furry friend needs you to be in good enough shape to care for he/she, and you deserve a big dose of happiness

Take care of you