Have you thought about some sort of talking therapy? Since I started therapy a couple of years ago I hardly get anxious anymore. You can also get medication for anxiety. I'm not sure about paranoia though, I'd think again therapy might help though. But your doctor would be able to give you more advice.
If you want things you can do yourself though to help you get through a day of work or something, breathing techniques can really help with anxiety. Having proper control of your breath can help you control your heartbeat and lessen that feeling of it all bubbling up.
Have a search online for the three-part breath. It's called dirga pranayama and is a yogic breathing technique to calm your breathing. You could also try meditation which would help calm your mind and your thoughts. Yoga too. It's all about calming everything down and relaxing. You'll get the best benefits out of it if its something you practice regularly, and you'll get better at it too.
I hope this helps. Let me know if you look into any of it *hugs*
jj