Very sudden and random case of ED...is it from an STD? Is it permanent?

[random624]

Last week, I had unprotected sex with this girl who I've only known for a little less than a month for the second time(stupid I know), and very shortly afterward I felt a itchy twinge at the tip on my urethra. I have had a case of chlamydia once before about 3 years ago, and the symptoms started in a similar fashion. However, there are some differences that make me question what this actually is. When I caught chlamydia, I had white/yellowish discharge that had a distinct odor and it hurt like crazy to pee. My urethra also constantly was in some level of pain/discomfort throughout the day. In this case, I felt the twinge about 2 days afterwards and I got the discharge a couple days ago on Wednesday. I confronted her about my symptoms and she told me that she has only had unprotected sex one other time a while ago but that she did have a history of a reoccurring yeast infection and that's what she thinks it is. Of course at first I believed that was ******** until I looked up male yeast infection symptoms and saw that it was very similar to chlamydia symptoms. I saw that although rare, it wouldn't be impossible if you had a weakened immune system which I'm sure I have because my diet has been terrible, I have a cold, and I have been extremely stressed out for the last 4 months due to me loading myself up with high level course work(I am a senior computer science major) and even more-so this past week due to midterms. I haven't been able to get to a clinic yet because I have been doing allnighters for these tests. The reason I am so scared now is because I have just recently noticed that I haven't been able to produce a full erection AT ALL. I first noticed  yesterday when I tried to masturbate and I had like a half erection. Today I tried to look at porn which literally never fails, and nothing at all. I'm extremely worried and concerned, I really would like to get to a doc and get tested right now but its Saturday and I'm dying.

Things to note:
-Took a 70mg vyvanese pill(Not perscribed to me) for my first time to cram for my exam on Wednesday night(I did not sleep that night)
-Next day I took half of one and only slept for about 2 hours
-Took another 70mg Friday morning and I slept for about 4 hours last night (Not taking anymore of those, it was a one time thing for studying)
-I smoke marijuana often / drink very sparingly
-I've been fighting athletes foot for some months

I have already decided that it's time for a major lifestyle change and I am stopping my use of weed and no more study pills. I need to get alot of rest and to get my diet together because stressing about this is a=going to make it worse.

Could this be a yeast infection or chlamydia again or something worse? And is ED permanent?