I'm sorry to hear you going through such a thing. I understand completely how it feels as I have problem doing everyday things (like shopping!) but have to force myself through it in any case.

I agree with gayleggg - breathing exercises help. I think it is because it is linked to mindfulness exercises. Initially it may not feel like much and you might have to do it multiple times a day, but the more you do it, the more benefit you will find out of it.

I still have the problem that you describe, but I started meditating and it is starting to take the edge off. If you can find classes in your area with a teacher, this is probably the best way to be guided. Otherwise there are loads of free sources on the internet and audios you can stream which can guide you.