It's possible, but it could be that or something else. It does sound like some type of infection. Here is a link to an article about lyme and also a link to some resources including two companies that give the newer blood tests. (The old mainstream test currently being given is known for a huge percentage of false negatives). I would suggest testing to rule it in or rule it out.
There is also the possibility of mycoplasma. Search this site for info. You might also consider looking at curezone for info on killing parasites and candida. If nothing else tests positive, I would look at these things.
In the meantime, please be more careful about the sex thing. Really - abstinance will never kill you or make you sick.