First things first - how long have you had symptoms? The longer you wait the less likely you are to get an accurate diagnosis if indeed this is herpes going on. Also delaying treatments means the less benefit you'll get out of the herpes antivirals too if you do indeed have herpes. I'm guessing you are not going to be seen this weekend by your regular doctor so I encourage you to find an acute care clinic to go to to get a visual diagnosis and proper treatment.
Worst case scenerio - you really do have genital herpes. Stop letting the IDEA of having herpes control you and further educate yourself on this pesky virus. It's far more common than you think and it's only a big deal if you let it be. Soceity has unfairly stigmatized herpes since it's sexually transmitted when it's genital and most folks are uneducated about it and therefore fear it needlessly

Check out the info here on asha. Also there is a terrific patient counseling video and the herpes handbook over at
www.westoverheights.com. You need to find out if you have hsv1 or hsv2 so if by the time you are seen by a medical provider the lesions are too far along to test - get a baseline type specific herpes igg blood test now and then repeat it in 3 months. That will help you try to figure out if you have hsv1 or hsv2 genitally and will also help you figure out if it's a newly acquired infection for you or just your first obvious recurrence of a prior infection. Even though folks assume that if they are just now noticing symptoms that it must be a newly acquired infection - over half the time it isn't so the baseline testing is worthwhile.
So about this gal. Go talk to her about this instead of ignoring her. Tell her that you aren't accusing her by no means but that since you two have had sex together you have developed some lesions in the genital area that you are going to be seeking out medical help for. Tell her that you have no idea if it's a new infection or not or even what in the heck it is. Suggest that while you are working things up on your end to find out what is going on she should probably set up an appointment this week to get herself worked up too in case she has something and doesn't know it. She should get herself a type specific herpes igg blood test too to know her status and if it's negative she should consider repeating it in 3 months too. Like I said - don't be accusatory - just be straight forward and present the facts and go from there.
Your coping skills must be fairly limited if you are turning to drugs and alcohol even before you know that you have anything. do you always assume the worst and then turn to such negative behaviors? if so perhaps you should consider seeking out the advice of a professional and work on that. Trust me when I say that life is going to throw things a lot more complicated than std's at you!
betsy