scared_as_hell

Two and a half to three weeks ago I noticed a small rash on my foreskin. I wasn't too worried, because I've always been quite sensitive there, and as a matter of fact, had an outbreak of eczema over the whole apparatus as a child of four or five. The other reason I wasn't too worried is that I am in a completely monogamous relationship with a woman I love dearly and I haven't so much as touched another woman for at least a year and a half. A day or two later, when the rash developed clearly-defined edges, I began to worry in earnest, but decided "wait-and-see" would be the best approach. Sure enough, the little splotch started to clear up. After a week or so, the skin had returned to normal color, leaving a very small area of skin that looks tighter than the skin around it, almost like scar tissue. Great, I thought. Until I checked it a week later and it was red again, with what looked like little bumps here and there. Heart attack, anyone?

So I went to the doctor and asked him what he thought. He thought it might be herpes, but when I told him I had had it for over two weeks, he seemed surprised. He said he thought it could be herpes or eczema. He didn't run any tests, just told me that since the eczema treatment exacerbates herpes, he was going to give me the herpes treatment and have me try it for a week to see if it works. (I'm rather put off by this approach and am beginning to doubt his professionalism-I need to know what this thing is if I am going to get any sleep at night).
So far, I've been putting the stuff on for four days, and it doesn't appear to be doing anything. The rash goes red, then pink, then red again, varying from day to day, and I don't know how much longer my mental health can take the anxiety. I'm terribly concerned for my girlfriend. If it is what I hope it isn't, and I've been carrying it around for two years unknowingly, then odds are she's got it already. But I can't say anything to her until I know for sure what it is. She has a terribly stressful job and I'm worried for her health as it is. I can't add more stress to that if it's just going to turn out to be a false alarm. But then what if it's true? I have a responsibility to tell her and get her checked. I'm terrified of losing her, for example, if she thinks I've been screwing around behind her back.
It's just too much for me to handle right now. It's a medical and ethical situation; I've been praying for the past two days, torn in two directions, wanting to get better but at the same time, hoping that this cream doesn't make a difference so it wouldn't be the big H. I'm topping out on anxiety. Does anyone have any words, thoughts, anything that could help me through this? It would be much appreciated. Thanks.