Hi Melisa,
35 is not too old to begin at all. I just determined I was trans at 34 and began HRT less than 2 weeks after my 35th birthday. All this while married with 2 kids and the birth of our 3rd. I can be done.
The hard part is getting onto a path that gets you where you wish to be. Talking with a therapist, particularly a gender therapist, can be incredibly helpful. Especially, if you are unsure about how you wish to deal with being trans. I did not have access to an informed consent clinic where I live. Therefore, I went through therapy to get a letter. Day 1 I told the therapist what my goals were and that I was there primarily to get a letter for HRT. She was a good therapist and we discussed a number of transition related issues. I ended up receiving my letter after 3 month of biweekly visits.
The changes from her are good. My body is responding more rapidly than I hoped. My mood is much more stable and I am able to be a better husband and father than before.
Fear not about the being a lesbian thing. I don't quibble over nomenclature. I am still very much attracted sexually to ladies. There is a bit of jealousy sometimes over particular aspects of appearance. There is no need to get bogged down into the details of all the sexuality parts of it. As a non-op people have a hard time wrapping their brains around the genitalia and orientation part of things. I just tell them to others we appear as a lesbian couple. In the bedroom is none of their business.
Hope to see you around the forum.
Hugs,
Amber