I am sorry your B/F is not tolerating your anxiety and that is sad but I believe the best thing you may try is to ask him to come to a therapy session with you and ask his questions of your therapist who can explain how he may best help you.
He may not agree to this and if he is at a point where he is not interested in supporting you than you may have to consider him someone that will not be there for you.
I know this seems so unfair but hiding your anxiety will make you worse. Overcoming your anxiety and learning how to deal with it is your best choice for yourself. This is your disorder and remember anxiety does not control you, you control it.
It is not your fault that this has happened to you so blaming yourself for the change in your relationship is unfair to you. Please don't do that to yourself. You cannot control your B/F's behavior, only your own.
Please work with your therapist and put your first. Keep posting here and know we care and we will support you.
A slip of the foot you may soon recover,
but a slip of the tongue you may never get over.
Hey purple dream-
I don't know if this will help you or not, but here goes. I was 22 when I began having major, major panic attacks. I was dating my husband at the time. Of course he didn't understand what was going on because I didn't understand it either. But he was there for me - he became my protection; my security. To this day (almost 14 years later) he still knows and understands my limitations - he is always right by my side when I need him.
However, it has also not been that easy. There have been sooo many times over the years that he has gotten frustrated with me - he tells me I need to be a big girl and stop relying on him for so much. That is always hard to take, but I also forgive him, because I know deep down, he doesn't mean those things - he is just frustrated and doesn't know what to do.
He really doesn't read, so when I give him anything to read to understand my condition, he will read it and say nothing. At least I know he read it, and I'm ok with him not responding. I know from all the times he has come to my defense (with other family members who haev been very cruel to me) that he DOES understand. You know, men have a way of wanting to "fix" things and when they cannot, they get frustrated. I don't think it is any reflection on his feelings for you or how he views the relationship. And sometimes, they just don't want to be bothered either - they have much more interesting things to think about (you know sports, work, ect....) at least that is the case with my dh.
So maybe try to relax a little - I know how painful it is to get anyone to understand this condition. In all reality, only those who have BEEN there will fully understand. That is why You, me, all of us.....need this board. We are here for you!