I had a lot of nasty intrusive suicidal thoughts during my last depressed episode. I did some things similar to what littlemiss said. I tried to use "Teflon mind", where you sit and meditate and picture something like a stream with leaves floating on it. Every time a thought comes in your mind, let it slip out and fall on the leaf and float down the stream. You can also use a clouds image. I'll admit, I was so low I didn't use my skills properly and suffered a lot more than I really should have, but when I was able to focus it helped. I stayed out of the hospital even hough my treatment team suggested it several times.

You can make it through this. It probably does have to do with the sudden decrease in lamictal. I'm no expert but it seems to be a much larger decrease than what should have happened.