Hi mjb2010,
I'm sorry to hear about
your difficulties!
First off, I'd like to start with the so-called "trivial" things. You REALLY, TRULY don't need to worry about
your height. First, you're just a tad shorter than average. I.e. you're well within the normal "range". Second, attraction between individuals is much more complex than simple considerations of height. Sure, I must admit, a 6 foot woman may not want to date a 5'7" man. However, most women anywhere near your height won't care--they'll be looking at other qualities. E.g. from your post, you sound like an intelligent individual! Women love intelligence! Sense of humor, ability to provide or be productive (in the case they prefer not to be provided for, lol), consideration for others, honesty, etc. are all characteristics many women would find far more attractive than any one physical feature. It REALLY is true.
What you need to realize is that you belong with a person who treats you as good as you treat her, who is kind and considerate, who you can have fun with, and whom you can mutually support through good times and bad. As a married guy who has been with is wife for almost 10 years, I can honestly tell you that her appearance (while a plus :-P) is not why I'm with her. I love who is on the inside unconditionally, and when you
open yourself up to someone (a deserving someone) and see that, you'll know just what I mean. So, you don't belong with a person of any pre-defined appearance.
"I realize that I must first confront all of my negative thoughts, phobias, complexes, and so forth." <-- That, I like. I think that's a big step.
What you have to do is catch yourself in these thoughts, and as soon as you think the thought, do your best to ignore the compulsion to obsess and try to fixate on something else. E.g. If you're thinking, "what am I doing with her? She's taller than me and it won't work out because of that." Immediately re-direct your consciousness to different thoughts, like "she really is a kind, considerate person. I hope I can show her a good time and get to know her better, because I think this could work out for the 'long run'". While it's true that unconcious brain activity can compel you to obsess and become anxious, the circuitry in the brain works in such a way that higher order areas, such as those involved in producing thought, also can give feedback to those lower, emotional centers. I.e. you literally "can" influence your feelings through thought. And, the more you reverse the process, the weaker the thoughts you're trying to push out become. This "neuroplasticity" is the basis of CBT. It's easier said that done, and it feels like playing tug-o-war with a stronger, and evil, version of yourself inside of your own head, but it's worth it because being miserable is no way to live life.
There is no guarantee that this relationship will work out for you. However, it is guaranteed that if you let your anxious, obsessive thoughts influence you to the point where you would break it off you'll never know where the relationship will have ended up, and you will have allowed the anxiety to become even more influential over your decision making process. It's a lose-lose situation.
As for telling her, once you know her well I would definitely do it. I fully, completely, absolutely understand you when you say you feel ashamed. I feel the same way all the time If she cannot accept you and does not make an attempt to understand what you're going through, then I guarantee you didn't want the relationship to go any further anyway. Relationships are all about
support and consideration of one another's needs and feelings. Having said that, I would highly suggest you actually try to educate her on it. Many people have wild ideas about
what we are like and why we have to deal with anxiety/panic.
I hope you feel better soon!