I'm STRESSED OUT! - Another Testical Infection

Hi im 21 and wonder if someone can help. Im all stressed out since i've never had this before.

I've just recently found blood in my semin, right after s@x (1hour) my left testical became very sore and started to swell. I got to a doc asap and he said that i have testical infection. Now, im not a docter but to me the syptomes are pritty simple that it could not be my protestites glan since i dont have blood in my uran, dont have problem to pee or any burning during pee. My Winky :$ is not swar only the left testical up to about 10cm to bladder. Which probably is the tube i presume thats also swollen. Another syptome is lower pain in my left side pelvic. That just started now and is gone again.. but was bad.

Now, question is im on antibiotics for about 1.5 weeks now and swelling seemed to have gone down a bit and up a bit after touching and infestigating ot much, but when i was at the doc i told him while he was feeling my testical that the lower part of my testical is hard and swollen. Sore at the time but not anymore. Now this hardness was never there and nor was it that roundish/swollen. ? Is this normal and what antibiotics should i take ? He said 2-3 weeks been 1.5 and i stress out. Please help? :-(