Having anal moisture can happen due to excessive sweating and especially so if you are overweight. Washing frequently and drying properly as well as wearing clean cotton underwear every day may help. Avoid manmade fabrics, these do not allow the body to breathe and will make you feel more damp and sweaty. Applying a medicated talcum powder to the area, or some Bicarbonate of Soda will help to keep you dry.
The other problem may be due to a bowel leakage. If this is the case, make an appointment and discuss this with your doctor as you may have diverticular disease or there may be a problem with not emptying your bladder sufficiently.
Best wishes.
I take it you've talked to your Dr about this before? If not, you really should. Some men sweat more than others and I'm wondering if this may be the problem. Have you tried powder to see if that helps?