AITAH for being in this kind of relationship and trust her?

I've been in a relationship for the past four years, and I'm still in it. However, things became difficult over the last year, and she broke up with me in October. Naturally, I was depressed. After 2–3 months, I started to feel a bit better. One day, she came back and asked if I was over her. I told her she was the one who left. After a lot of back and forth, since I still had feelings for her, we got back together.

Then she told me that during our breakup, she was in a relationship with someone else. I forgave her — that’s not the issue. The problem is that now, even though we're together again, she says she won’t treat me like we're in a relationship. She won’t even say "I love you" back. Her reason is that she still hasn’t gotten over the emotional trauma I caused her in the past. She says the next step will be marriage — nothing in between.

Now I’m confused. I don’t know if I should trust her or what I should do.