I NEED HELP FACTS AND PRAYERS!!!

I never thought that I would be typing something like this.  I'm 26 years old and do not have much of a sexual history about 5 people.  5 years ago a friend of mine that I had a crush on began to date and we have been together ever since.  We were married on October 28th and this year will be our second anniversary.  I love this woman with all my heart but earlier this year we were having a lot of problems and i did not know if our marriage was gonna last.  My wife had been having problems binge drinking and I have been battling depression and a bipolar disorder for a long time.  The zoloft i had been presribed seemed like it had lost its effectiveness and I was really close to losing it.  During this time I met a young lady after one of my concerts as I'm a part time musician through a mutal friend.  It started out innocent enough as I have a bit of a flirty personality but have Never cheated before on anyone.  The girl was quite attractive I won't lie so I wanted to see about her modeling some of our T shirts for us.  Well one phone call lead to another and another and we eventually began hanging out just as friends and as someone I could talk to during all of the shit that I was going through as she was a good listener and so am I and we would talk about eachothers problems.  Earlier this year she was in a relationship and her boyfriend had commited suicide. I'm sorry if this seems like rambling but I'm just trying to  tell the whole story.  Eventually our relationship became intimate one night out of passion it just kind of happened.  We were making out and she was teasing me by rubbing herself (genital) on me until she decided to go all the way.  Once she did I couldn't stop and am not going to lie did not want her to at the time.  We had talked previously about sexal history and she was kind of vague except that she told me that she had been tested at the health department on a few different occassions just as an active sex single adult.  She told me I did not have anything to worry about.  We did not use protection as she was on birth control and I am so use to being in a monogamous relationship and everything happened so quickly.  I was so ashamed and still am to this day for cheating on my wife but I couldn't help at the time that here was a person that was actually genuinely interested in me and listened to me instead of judging me.  Our friendship continued secretly since April and we were probably not intimate until July.  I did grow to have feelings towards this girl and have trust in her and since that time we engaged in unprotected sex a handful of times.  That is not what our relationship was about I mean if I was single it would be considered "friends with benefits."  I never lied to this girl and she knew from the start that I was married but apparently we both just kind of fell for eachother at a time when we both needed someone.  I'm not trying to make any excuses I know what I did was wrong trust me.  I continued to want to be friends with this girl but my wife and I's marriage has been back on track and did not want it to continue sexually.  After three medication changes over the course of this time I think I had finally been given something that actually works again.  And during all of this my wife and I's marriage has gotten much better and it might be weird but i think it had to do with my affair.  Now let me bring you to the present.  It's been about a month since any sexual contact with the "mistress" we still have talked but no sex and no intimacy.  Last week my wife and I had sex on wed. and we have had a somewhat normal sex life during all of this (1 to 2) times a month.  I did not take a shower after my wife and I had sex just simply went to sleep.  On friday I noticed red/skin colored little blisters on my penis and some itching and figured ok I just have a rash or something trying to be optomistic.  But guilt/curiosity got me looking on the internet on std's since I have never had one and my wife has not.  I called the friend and