Thank you for responding Marianne. A lot of what of I have found is trans porn, but also browsing trans forums and trans posts on twitter. I noticed he started following some trans people on twitter (non-sexual content). He tells me he was just curious, but his internet history also includes searches for sexuality types and some searches for nonbinary emojis. I just don't know what to think. He's always been sympathetic to the LGBTQ community and has always liked watching documentaries about trans people. I thought he was just a really open minded person. It's obvious he has always felt insecure about his masculinity. He used to say to me "I'm a man", often, if I ever joked about him not being able to do something or sometimes unprovoked. It got to the point I said why do you say that. He has since stopped. He's always been very submissive. I handle all our finances, bills, literally everything. I used to think to myself for years he was like being married to a woman. He has said many times to me women are lucky because they have nicer clothes. He's really into the way he looks, clothes, etc. He started growing his hair out right around the time I found the trans history and now keeps his once goatee clean shaven. We were playing a video game once and when he saw my female character he said wow you're beautiful. Then he said maybe he should make a female character. This was before I had any suspicions and I think I just paused and said something like ok if you want. When he heard me hesitate, he was just like no I won't. I never thought anything of it. I feel stupid for not noticing things like that. We have had so many problems with intimacy. I have to initiate most of the time and have been rejected so many times. I'm so confused because while I think he could be questioning his gender, sometimes I wonder if he's gay. Or maybe both? Dysphoria? If he sees male nudity on tv he gets awkward and looks away or comments about how it's gross. It's been a year since I found the internet stuff and this is the first time I've told anyone about it. I've always sensed something was off. We're both in our 40's and have been together for 16 years. I love this person very much. There is so much more and it's just so hard to hold all of it in. It's so hard to hear him tell me I'm crazy and dead wrong when I can literally see with my own eyes that something is up. I doubt myself all the time and wonder if I'm putting myself through this for nothing. I wouldn't wish this on anyone.

Lemma,
   My (now ex) husband who one day declared he was "a woman in a man's body" had never exhibited anything that would have suggested he was anything but a man.  Not a hyper masculine man, but a man.   Subsequently I found out he'd been hiding many things from me, and most of them you have described: browsing trans sites, watching trans porn, identified with women (referred to himself as a male feminist).  After his declaration, he shaved his beard, wanted to shave his legs (actually, he had a fantasy that I would shave his legs!), and revealed that for years he'd been filching my undergarments when I wasn't home and wearing them.  
  I agree with Marianne.  Your gut is right on this one.  Trust your instincts.  And remember, sometimes things we love are not good for us.  

If you take away the cross dressing etc, what you are left with is a male who is attracted to men and wants to be the submissive one.  ie he is still gay.

I can understand why they'd like to dress up as women but the medical interventions to try and look like a female, goodness I don't understand that, it seems entirely crazy to me to mutilate your body so much, it is not going to make for a comfortable old age, is it.  But then people stick staples in their nipples so what do I know!

Lily,
 At least half of the men--probably more--who declare they are transgender remain attracted to women.