Bottom growth? I am sure you mean penile or clitoral growth.
After 3 years, assuming hormone blood levels that are in the typical male range, you should be seeing about an inch of length. Being overweight will definitely bury almost all of this growth with subcutaneous fat. Being overweight will produce Estrogen by itself. Just take a look at overweight men. Many have buried penises.
Have you had a hysterectomy or your ovaries removed? Have you had your Estrogen levels measured?
There are a few issues here that need to be addressed.
In my opinion, losing weight and a metiodioplasty will give you all that you are going to get with this route, assuming that your hormone levels have been proper for the past 3 years. I have seen pictures of thin transmen with about an inch and a half or almost 2 inches of a very good looking penis after a metiodioplasty. They also report very good feeling and significant sexual function.
There are surgical procedures that can produce a larger penis, but function and feeling are not as good as a metiodioplasty.