Why would I tell him when I'm feeling shitty about the fact that he can never be mine in any meaningful way (or any of the other feelings that come with this situation)? That would just make him feel guilty which is useless.

It didn't work the first time when you didn't share your feelings, so why would you do the same thing all over again (i.e. not share your feelings), expecting a different result?

I have a common theme that I say to my AP in a variety of ways, but basically, what I tell him is we're in this together. When you care about someone, you want to be part of the good and the bad in their life, and this is what he's telling you. He wants to know when you're struggling before it becomes too much for you because you've repressed those feelings.

I am expressive of my feelings, and that sometimes includes me saying that I'm bummed out at our situation. I would like it to be different, but I know, "it is what it is" (an appropriate use of that phrase!). I know that he would like it to be different, too. That doesn't mean it's possible, of course. I don't tell him that to make him feel guilty or to try to get him to make a promise to me about some future plans. Instead, I just want him to know that it's not always easy on me, and even though it's not, I still want to be involved with him because he's worth it.

I used to be so afraid to express my feelings unless they were 100% positive, but that's not healthy. It isn't good for a relationship, either. I've really learned since being involved with my AP to not repress those negative feelings, whether it's something he can "fix" or not. I guess that's the distinction to make clear - many men hear "problems" (or what they perceive as problems), and they believe that they have to try to fix them. But, I'm not looking for him to fix this - maybe offer some words of understanding, but that's all.

One final point - you ultimately need to decide if you are OK with an affair that isn't going to be more than an affair. My AP and I are both married, so it's different. If I were a single woman at your age, I would not get involved in a long-term relationship with any man who was physically and/or emotionally unavailable. It would not be enough for me.