I will give you best advice that I can and I can almost guarantee it will help them understand.
I was in the same situation and my boyfriend couldn't understand what the hell was going on and all he would do is complain and think I was making it up or the least exaggerate it.
But instead I gave him a book called 'Living with IT' by Bev Aisbett - it was recommended by my counsellor and psychologist. It is the best book for someone to understand anxiety whether you are suffering it or whether you are affected by it.
It has really helped him be more understanding and supportinve of me and I can almost guarantee it will help if they are willing to read it. Ijust posted an amazing story about something that happened to me, see if you can read it.
Good Luck!