Again, my friend Cuch is spot on. The only thing I might add, coming from a woman's perspective, she told you straight up that she isn't interested in a relationship because she would just push you away and that she doesn't really care if and when you call or text her. This all definitely could be part and parcel of her disorder but, it also could mean that she simply doesn't want a close relationship with you regardless. We do tend to come across as being cold, just like Cuch said and it is a defense mechanism, but I sense that you are hoping this relationship will turn around to being more than she is willing to give. It could happen, but my gut is telling me it won't especially if you frequently try to keep in touch with her. You've told her already that you will always be there for her, so give her the odd phone call or text every now and then, but don't over do it. She has your number, she can get in touch with you if she really wants to continue a friendship. We tend to have precious few friends because of this disorder, but I wouldn't want you to get your hopes up that some day she may change her mind and fall madly in love with you. She could very well just simply not want a romantic relationship with you and is trying to let you down gently. I've done the same thing myself in the past and yet, I am now married for 35 years. So obviously, I was willing to give it a go with the right person for me.
Basically what I am saying here is what Cuch says is spot on, but sometimes people use excuses to try and let someone down gently that they don't want a relationship (either friendship or romantic) rather that telling them in a nasty way, to go away, I don't want you in my life. Just because we have an anxiety disorder doesn't mean that we are different than others in how we try to get out of a relationship. I'm sorry to be blunt, but you do have to consider that this could be the case here. She knows you are there for her as a friend, so the ball is in her court. If you are looking for a love interest with this girl, you could be waiting forever and possibly passing up great opportunities of meeting the "right one". You are obviously a great guy who is willing to be there for this girl, I would just hate for you to be wasting your time on the hope that she may change her mind when you could be with someone who really cares for you.