What's the deal with me sabotaging relationships?

My girlfriend and I (I’m a girl, as well) are “putting things on hold for awhile”. She said that she needs time to see whether she wants to be in a relationship. Here’s the thing; I’m the one who messed it up. Not by doing one big thing, but, a bunch of little things. This is a l/d relationship that has been going on for about a year (we’ve known each other for 4 years). We see each other about once every couple of months for two weeks at a time. The idea was that in about a year, I was going to move to where she is (Texas). The last time that I went to visit her (a few weeks ago); I did a few stupid things and said a few stupid things. I’m not going to go into detail, but, basically it left her feeling that maybe, I didn’t think that she was the one for me. Which is so not true. I’m wondering if me saying these hurtful things (not intentionally, though) was because I fear that things aren’t going to work out in the long, so, I sabatoge things? It ends up being a self-fulling prophecy sort of thing. I end up messing up the relationship.

I guess that probably should say some of things that I did. I was sick with the stomach flu and we were sitting on the sofa watching a movie, I got up and said that I was going to bed, but, she didn’t have to come with me. I told her to watch the movie, if she wanted to. She insisted on coming with me and I proceeded to tell her (big mistake!) that we don’t have to be on top of each other all of the time. Yikes.

We went out to a bar; she was dancing with a friend and I was talking to a couple of guys. She was hurt that I wasn’t dancing with her. When I was Austin, I went ahead and made plans with a new friend. She’s straight and we were getting together for lunch. I didn’t tell my g/f until the day of that we were getting together. My g/f was going to be at work and I thought it would be fun to go for lunch with this friend (who I have no interest in). My g/f never met her and I kind’ve sprung it on her that this girl and I were going to for lunch. She was upset by that. I told her afterwards how sorry I was and that I ‘get why she was upset’. When I was drunk, I made a stupid remark about a paper cigar ring. I said that it will probably last as long as our relationship. I said it jokingly at the time. But, why would I say that????

To tell you the truth, I felt closer to her this time around (of getting together). I truly love her and I don’t get why I did/said these things. She also has an ex who still cares for her that I worry about. The ex lives there and I live 1000s of miles away.

Any help/advice would be appreciated.