An endocrinologist is not the best consultant for premature ovarian failure, you need to see an informed gynaecologist who can put you back onto your patches or gel with the appropriate progesterone, if the endo is so concerned about your heart, surely he should realise that by not taking HRT at your young age, that could be more detrimental, silly git! I also went through it and was on hrt from before the age of 40.
I would put myself back on it if I were you, relax, measure your bp at home as others have said white coat syndrome happens, it certainly happens to many of ours & that reading is really not high. I doubt a cardiologist is needed, more like a good gynae. But do try and stay on your patches you need to keep your levels up to protect bones, heart etc and transdermally is really a great way to do that. Strongs.