Knee pain after working out

HazyEyes93

So, I'm no stranger to things like HIIT. It has been well over a year since I have worked out or tracked food, thus gaining back 40 of the 120lbs that I lost a few years ago. So, I'm in my second week back on the wagon, but I seem to have a new obstacle. KNEE PAIN. And I don't mean a little sore, I mean throbbing and swelling. I don't just get it when I'm working out, either, but also really long week at work.

I'm only 23, a little less that 20 lbs overweight at this point. I don't understand how one workout could cause that much joint pain. Not just my knee, either, my hands as well.

I also work an insane amount at a very active job. Think 100+ degree temperature, not sitting now for 15 hours straight, a lot of lifting and a lot of running. I can also easily work 12 shifts in one week. I'm trying to wrap my head around what is actually realistic for me as far as fitness is concerned. I'm barely getting by financially, so working less it really out of the question and this isn't the kind of job that I can do well while in a lot of pain. I've gone home because of joint pain before and I don't want to exacerbate it or do irreversible damage.

Maybe HIIT and circuit training are just out of the question for me at this time? Should I look into more low impact options like yoga or pilates?