When I had my hysterectomy my doctor inserted an oestrogen implant and within 24 hours I was feeling better than I had in years. It's now 29 years later and I am still on HRT. I don't intend to give it up as my quality of life is so superior thanks to that little pellet of oestrogen that I get twice a year. In your place I would grab the opportunity to get my life back. Weight gain is caused by eating more calories than you burn off. HRT isn't going to affect your weight unless you eat more and with all your renewed energy when you are back to your old self you should be burning more calories, not less. Why not try it?
I would advise any transdermal method (patches, gel, implants etc.). Don't take pills as they have to be a much higher dose as it has to pass through the liver first.
Your symptoms are caused by lack of oestrogen, replacing it is the natural way to return to normal.