I think that I may have been exposed to herpes, the problem is that I have been sexually active with my partner for the last seven years and only him. I just begin to have these symptoms about a month ago. I let him know about this and he says that he has no symptoms. Is it possible for only me to be infected and not him.

It is possible he has had it for years and has no symptoms. (and you just got it from him) It is possible you had it for years and never noticed until now.

So it is possible only you have it but get it checked first cause it very well may be something else.