<human>: Can you condense the text into a few key points?

Hey everyone,
I've been with my current girlfriend for a bit over 4 months now, and I think we have a pretty great relationship.  We're completely open with each other, and we both care very much about each other and what we have. Recently I've started feeling anxiety in the relationship. I should mention that it started at school, and we live about 2 hours away now for summer and fall.  I've always put pressure on myself to do the best I could, and there have been times when I didn't feel like putting in all the effort I could. That scared me, and made me think that maybe my feelings were changing, even though I still wanted to make her as happy as possible, and to continue the great thing we have.

Last weekend I was at her house, and before I left I had a bit of an anxiety attack. I couldn't really tell why it happened, I do know that I was worried about maintaining the relationship we had while apart, even though there's really no danger of anything bad happening. I woke up the next morning, and it seemed like all of a sudden I couldn't even talk to her without feeling anxious. It's starting to get a little better, but I still have a lot of moments when even thinking about her brings back the nervousness. I want to do everything that we normally do, i.e. talk, laugh, see movies, typical relationship stuff, but it feels like something (or myself) is holding me back from really acting on it, and showing her all the love I can. 

I know that she'll help me through anything I go through, and will love me for who I am, but for some reason I still worry about doing enough. When I start feeling the anxiety, sometimes I can't tell whether I'm just worrying too much or if my feelings are actually changing. She's someone I can see myself being with for a long time, but it feels like the anxiety is getting in the way. I'm talking to someone tomorrow about it, but I wanted to get some more thoughts on this. Has anyone else experienced something similar? Any thoughts? Thanks for any input!
<bot>: Has anyone else felt that they are holding themselves back from giving and accepting love, especially when you are feeling some anxiety in your relationship/life?