Hi pregy, welcome.
I have 3 children, and I know what this feels like. Unfortunately I don't think you can take any meds during the prego. So you need to find ways to self-soothe. I think a lot of these feelings could be normal for anyone about to give birth - this is a big deal! I find myself talking to myself when I feel this stressed out, I'll talk myself down, sometimes out loud, sorting out what is worth raising my blood pressure and what isn't. The breathing techniques we learn for labor are good - not the fast ones, I never liked those, but the slow deep breaths. I used meditation. I'll try to remember more about what I did during pregnancy to calm down. And I'm sure more folks here will be able to offer some suggestions. You're in the home stretch, in 6 weeks you're going to have your beautiful new family member who you will love with all your heart.