Do I need to go to the hospital if I think I was drugged?

Yes. You need to go to the hospital and call the police. They will be able to do tests on your blood to see what the problem is.
Yes. There are two reasons why. First, and most important, since you may not know what you were given, you should be screened, tested and observed. There are countless things you could be given some of which may be life threatening for one reason or another. The second reason would be for potential legal reasons in documenting the case.