I dont have alot to offer but my wife went thru the same thing when she was late teens and she didnt get help then but does now for various things and weight is one thing that causes her alot of depression and anxiety ,she is dealing with the weight issue much betternow all I can offer is I think you are doing the right thing by seeking help and goodluck
God grant me the serenity
to accept the things I cannot change;
courage to change the things I can;
and wisdom to know the difference.