I don't know what's my fault and what isn't

I try and be really proactive about my anxiety in my relationship and work out what I can do better. I'm constantly trying to work on it and not let it hold me back. But I feel overwhelmed by the sheer number of issues I seem to have. Basically what happens is that I speak to my partner about an issue, or something I'd like her to do differently, but after some talk about it I tend to realise (or so it seems) that it's probably my fault. A frequent example is that I start missing my partner more and feeling somewhat neglected (we're long distance) but I usually end up thinking that it's just me being needy. I end up backtracking, withdrawing what I asked her to do and saying I'll be better instead.

Naturally this confuses her. She doesn't like when I backtrack in this way because in her words it weakens her trust in me and she doesn't know what's something she needs to work on and what isn't. And I understand that, I do, but at the same time I'm not doing it deliberately. I don't set out to have a conversation and realise it's my fault. It just happens.

Now the real issue is, I don't know ​if it's my fault for sure. I'm sure at least some of it is but I don't think she's helping the situation very much either; but if that's so, idk what I'd prefer. My confidence feels so shot down by now; I don't trust any of my thoughts. I wish I had a therapist to talk to but I can't get that in place just yet. I have no idea what's anxiety and what isn't here.