Interview skills /eye contact at interviews

Hi,

I struggle a lot with anxiety during interviews* to the point of crying and being unable to make any eye contact at all. 

It's limiting my opportunities in life and I'd like to get to grips with it. I've read up on general interview/presentation skills  online, but wondered if anyone here has found some useful 'hacks'?

* GP and dental appts. too. Seems to be any situation where I really need or want something. 

Many thanks