Interesting / Confusing Relationship Situation

Hey everyone, this is my first post on here so please bear with me

I've been dating the same girl for about 6 years... with a few breaks / breakups in the mean time. We are currently not together right now... we broke up in January. I was devastated and knew that I would do anything to get her back. Reasons for breakup... lots of stupid arguments... and she felt that I didn't think she was "special" to me anymore and that I "took her for granted". I don't really agree with these things, but I told her I understood. I can kindof see where she's coming from I guess, but I think that after a very long time of being together, things DO become a little routine... am I wrong to think that?

We went a couple months without talking... then she slowly started to creep back into my life (I was very thankful for, but now am more confused than ever).

We have seen eachother about 6 times in the last month and a half. We have had some intimate contact as well (which is something she DOES NOT do outside of a relationship).

I have also written her a couple really nice, thoughtful letters... not BEGGING for her back, but more of just letting her know that I still love her and have feelings for her and would like to get back together. She has also said she still loved me and has feelings for me, but is just nervous / scared that we could end up breaking up again or that things could go sour again. I told her that I've changed and matured a bit and realized how to better deal with problems with her, and she said "we'll see".

She also told me that in the 4+ months of being apart, she loosely dated someone... but it didn't work out and she said it didn't feel right. She also told me that the last time she and this guy went out, she came home and called me (didn't tell me where she previously was, though) and we talked for over 3 hours like old times.

Also, we talk just about every night on the phone, she calls me, and usually exchange a few text messages throughout the day, which I usually initiate.

She alludes to the fact that things could work between us again and that she misses me, but that she is also "in no frame of mind to be anywhere near ready to be back together yet".

If you guys could share your thoughts on this situation it would be greatly appreciated.

I love this girl and want nothing more than to spend the rest of my life with her, I've had time to imagine and try out what it'd be like to not go back to her, but I've realized that I know what I want - to be with her.

I also don't think she would have started talking to me again and calling me at night if she didn't at least somewhat want this too.

Thanks!