I think you should try to persevere. There will be ups and downs with any med you take. Keep at it. If and that's a big "IF" you start feeling a little depressed in a few months then you COULD try an AD but titrating it up very slowly. I have terrible start up SE's and had to start citalopram in 2.5 mgs a day for the first two weeks so it is possible. However, don't think about that yet. Its still early days on Pregabalin.
So are you on 300mgs a day now?
Sarah