Lymphnodes are usaly the size of a pea if you dig,push on them or keep feeling around for them they will definately swell up . Lymphnodes swell up for many reasons if you accidently hit one that can also cause them to swell up . Rashes are also caused by any number of reasons and you can't realy judge by them either the only way to know for certain is to get an hiv test
(WHICH YOU HAVE DONE)
The rash could be a bacteria infection caused by deoderant or soap or laundry detergent ........
The discomfort could be a urinary tract infection
(JUST DON'T POKE AT YOU'RE LYMPHNODES)
It makes things worse get checked for everything A-Z ..............
I'm sure you're fine but it never hurts to make sure ...........
I hope you can sleep better knowing you're (HIV NEGATIVE) relax and get checked out for other stuff ..................
Stay safe

In good health ..........
........... Lost spirit ....................