You have a few separate issues here by the sound of it.
A Gender Therapist can help with the Trans stuff. A Psychiatrist is better then a Psychologist, who is better than a Therapist, but anyone who knows the subject would be a help.
Weight is a health issue, how you look is irrelevant if your heart attack risk is increased. Steady exercise like walking or cycling a few times a week will do it, if you keep at it. Cutting down on fat and sugar intake is a big help too, but don't deny yourself a SMALL treat very occaissionally, as a pleasant diversion, not a reward.
As you lose weight and get fitter you will feel better about yourself and have more confidence. That, coupled with the endorphins will help alleviate your depression, and a psych can help here as well.
You can do it. It's a matter of asking , "what is needed here?" and doing it.
Karen.