Hi
@smarrero I can completely empathize with what you're going through. As a supporter in love with a combat PTSD guy for more than 2 years now (I only got clued in to what was going on with him thanks to this forum last fall), I can tell you that your experience is only too common. It's one of those clubs no one wants to join, but this is a very supportive community. Read as much as you can on here and you'll see your experience echoed over and over.
The first thing I had to teach myself to do is to abandon any thought that a relationship with a PTSD "sufferer" is an any way comparable to one with a non-sufferer. The world looks completely different to someone with PTSD. Just the fact that my guy finally told me he loved me last Labor Day seems to have triggered something in him that drove him right away from me.
As experienced supporters emphasize on here, you first have to educate yourself about PTSD in general, then about your own loved one's particular experience of it. Things that are counterintuitive and make NO sense to us non-sufferers are a natural part of the universe to someone with PTSD. The common theme here is that when a PTSD sufferer asks for space, they need space. Not giving it to them can provoke a very negative reaction. As long as he keeps coming back, to me that's a good sign. Let him know you support him and want to be there for him, however he needs you to be--this can include simply leaving him alone sometimes. The stress of dealing with even strong positive emotions can tip the stress cup right over. I wish I could say something that would magically help you understand and cope with this all at once, but that thing doesn't exist.
One of the hardest things for me to understand has been why my guy can act normally with friends and acquaintances and not want anything to do with me. It has to do with the intensity of an intimate relationship, which for PTSD people can be simply too overwhelming sometimes, hence the need to withdraw from you.
If you feel you want to be with him, show support, learn as much as you can, and unfortunately get used to a relationship that doesn't look like what you've been brought up to think a relationship should be. But if you and he love each other, if he gets therapy and tries, you can make it work--see the stories of several people on here who have done that. I've found that the love I've received from my PTSD guy is the strongest and best in my life. Wishing you love, strength and happiness, and offering hugs if you accept them.
Best,
Larksong