sorry if there is tmi here!
i don't know how relevent my advice will be because mine aren't really external hemorrhoids, they're internal, just inside the anus but 'pop out' and become visible when i am straining on the toilet for example. they don't give me any pain or itching, or any other bother for that matter. but last summer they flared up really badly for a couple of weeks. the first factor was that there was a heat wave so it was really warm and sweaty! the second factor was that i had a cold and was coughing almost constantly. the third factor was i got a new job where i had to lift heavy boxes. so between the heat and the coughing and the straining with heavy boxes, the hemorrhoids came out and they stayed out! it was really annoying, really uncomfortable. they're not nice at all!!
well i found that keeping cool helped a lot. avoiding doing things where you will be straining. if you are going to the gym and lifting weights and stuff then i'm sure you are straining so i would give it a little while before going back. i was always under the impression that when you have a hemmorrhoid it is pretty much there for good unless you have it surgically removed. probably it is always gonna be there but just certain times it will be more noticeable, or it will flare up.
you already have a good diet and drink lots of water so it sounds like you are doing everything you can do, really. try giving it time and relaxing. mine went away after that one time last summer and they havent annoyed me since so hopefully yours will be much better if you give it a couple of weeks.