I recently started taking Judo classes. I'd dabbled in wrestling, Aikido, Jujitsu, Kav McGraw, and Karate, but had never tried Judo.
I woke up Sunday after my 3rd class this week on Saturday, and was so sore I could hardly move.
New challenges bring new aches and pains- mental and physical, but over time you will grow stronger and adapt. The human mind and body are capable of much more than we think they are. New aches and pains are your body and mind's way of telling you that you are adapting.
Don't give up. As the ancient proverb says, "this too shall pass" and when it does you won't be the same. You'll be stronger.