Well, everyone thinks it's worse for the simple reason that it is! The only real manifestation of it before was when I got a bit OCD about washing my hands for a few months when I was in the last year at primary school, probably as a reaction to the underlying uncertainty of leaving and going on to secondary, even though in my conscious mind I was fine with it and actually looking forward to it! That was a walk in the park compared to the last couple of months however, so I suppose everyone I've told about it simply has to take it seriously.
I'm glad that your Mum knows something about what you're going through (well, glad for you but not so much for her that she knows about anxiety in the first place!), but I can only say again to try not to take it personally if she sometimes gets short with you. I don't doubt for a moment that she loves you and wants you to be happy, but reassurance is usually based on "See, it's not so bad" or "Even if the worst happens, you'll deal with it because...", so falls flat when faced with the toxic irrationality of a serious phobia. No matter what she says, it will always fall short of the absolute reassurance that someone genuinely phobic about something will always, by definition, want to hear.
I know what you mean about feeling isolated - I was watching a quiz show recently and envied the contestants larking about, thinking, "You don't look ill and I bet you're not stressed out that the last meal you ate will come back up tonight are you?" However, the way to look at it is to take it as a metaphor of what needs to happen now. (Being such a serious theatre-goer, you're perfectly happy thinking in metaphors aren't you?
) The truth is that, however much reassurance and support you get from your family or people on here, ultimately only
you can make yourself better, by seeking out a therapist that works and listening to what they tell you.
Yes, I do understand how you feel, but try to see it as a positive thing, gently pointing you in the direction you need to go next.