Ahhh, I just wrote out a long reply and then accidentally closed the window without posting it! How annoying. I'll try to remember what I put!
I'm really sorry that you're dealing with this; I can relate a lot and it is awful.
I'm sorry you haven't been offered any help with it. I wonder if it might be worth going back to your doctor and stressing again how much this is affecting you, or perhaps seeing a different doctor. If you have a family member or friend who could go with you and back you up that can be useful.
It is difficult when you don't know what triggers it as then you don't know how to tackle it or what to do to help. Are you able to identify any thoughts that you get when you're feeling anxious? Sometimes that can help as if you can identify any negative thoughts then you can start challenging them.
I can definitely understand not wanting to do things because of anxiety, but I think in the long run that is likely to make things worse. I've found that when I'm anxious about doing something the best thing I can do is push myself out of my comfort zone and do as much as possible anyway, as then I realise that nothing really bad happens and the next time is a little less scary. Don't be hard on yourself when you can't or push yourself too hard, but do keep trying to do as much as you can. I know it's difficult though.
It's good that the relaxation and breathing techniques do help a bit, and maybe if you keep using them and practising them it will get easier and you'll be able to use them effectively when you're feeling really bad, or even be able to stop it progressing to that point. I can tell you some of the things that I'm finding helpful at the moment, I don't know if they'll be useful for you but they're probably worth trying!
When I'm really anxious or having a panic attack I find that the type of grounding techniques that are usually suggested for helping with flashbacks can be really useful. There are some here [
http://www.recoveryourlife.com/index...5_articleid=2] and a lot available online in various places.
I find it helps to have something comforting I can hold and focus on. Also because I kind of lose touch with myself when I'm panicking, repeating my personal details to myself can help a little. I also get stuck in a cycle of being trapped in my own head and focusing only on the anxiety symptoms so anything that takes my focus outside of myself is helpful. I like counting things [e.g. all the red things in the room, all the round things, whatever].
There are some self-help courses available online that you could try using. ecouch[ecouch.anu.edu.au/] was recommended to me by a counsellor and has programmes for anxiety and worry, social anxiety, depression, etc. You can choose which one/s you do, depending on what is causing you the most issues.
I find listening to guided meditations or podcasts and such useful; as it helps me to focus on the techniques but also sometimes just listening to a voice can be comforting. The Mental Health Foundation has some good ones [
http://www.mentalhealth.org.uk/help-...ion/podcasts/].
Sorry for rambling! I hope you're able to find something that helps as dealing with anxiety isn't fun at all. Look after yourself and please PM me if it would help to talk.