Hyperhydrosis anywhere on the body can be very difficult to try to handle. In other parts of the body there are some treatments that can be considered and it's possible these can also be used here, too, but you need to check with your doc. They include: various prescription antiperspirants, iontophoresis (a procedure in which the sweat glands can be blocked), and more treatments such as botulinum toxin.
Baby powder in the area will hopefully minimize any smells but to control the sweating itself - get constipation under control and make sure your bowel movements are not diarrhea (as this can lead to the leakage). If you're regular and are having these problems then kegels might help regain that muscle in your sphincter, hopefully this will hold back any leakage. If the problem still persists, examine the area for any signs of fistulas or pilonidal cysts. The area may be inflamed and painful.
This seems to be a an anxiety issue. I also have this issue myself. It happens worst when I'm anxious. I have generalized anxiety disorder and it helps taking an anxiety med but anxiety med will not take it away completely as it is deeper psychological issue. I had a colonoscopy and hemorroids, but I also have bipolar disorder. Anxiety meds are narcotic and addictive and may worsen the anxiety if abused or used when not necessarily needed. Psychiatrists and doctors do not like to prescribe them because of drug seeking patients. The problem causes anxiety so it feeds on itself. Therapist may help to get to the root of the problem otherwise try exercise.