Do I have to change my speaking pace?

I'm a Thai who's now working and studying in the US and supposedly to be here for at least two years. I thought I'd had a good enough English before I came; but I was dead wrong! Language problem makes the expected culture shock even worse.
Reading and writing isn't part of my problem, it's listening and speaking that does. Even here in Texas, I found Americans speak very fast that they become only half understandable to me. When I try to speak with the same speed as them (and to mimic the 'accent'), everything goes worse. All my confidence's gone to pot. FYI, I'm a naturally slow speaker, even in Thai, which is a relatively slow and soft language.
So what's your recommendation? Should I practice speaking faster or slow down to my normal pace (which sounds so accented in my opinion.)
Thanks a lot.

Just talk at a pace that is comfortable for you, the whole point is that you are understood. I have to make a concious effort to talk slowly because no-one understands me when I talk at my natural speed, even though I'm talking in my mother tongue. You could probably still work on getting rid of your accent even if you spoke slowly if you wanted to. Good luck with whatever you decide though.