I had this problem in my teens, it was just on one side (no odour)
I went to the doctors and they referred me to a dermatologist, the treatments on offer included tablets which stopped sweating completely by blocking the sweat glands but it was all over the body so not really healthy! Botox in the underarm, anxiety counselling (as its usually caused by the anxiety of worrying about the sweating that causes you to sweat once its become a problem) or driclor which contains mainly Aluminium Chloride which is said to be not too good for you!
I opted for the driclor and it does work although it can be quite irritating. My daughter is 13 and has just started to have the same problem but I think she is too young for the driclor as aluminium chloride in deodorant was linked to cancer I think!
It's a horrible embarrassing problem! xx