I went through some serious anxiety when my DS was about 4-5 months old. It was just like you described, and it was awful, so I completely sympathize.

Do you know what it is that triggers your anxiety? For me it was some stomach problems I was having and I started worrying that it was something serious. The more I worried, the worse my stomach got and it just escalated.

What helped for me was getting out and keeping as busy as possible so I didn't have time to think about what was making me anxious. I found I was much better when I had company around me or when I was doing something fun, so I threw myself into different activities to keep my mind elsewhere. I never let myself sit around at home alone stressing out. I did end up going on meds for a few months until my anxiety settled down and then after that made sure I got out every day even if it was just grocery shopping.

I'm 6 weeks PG too and have been a little anxious as well since my last PG ended in M/C at 6 weeks. I am still making myself go out every day though (or I have friends with kids over for play dates) and I am making myself think positive thoughts instead of negative one.

Have you talked to you doctor? I found that helped me a lot too. I hope you're feeling better soon!