Let me start by saying that I am not a doctor, nurse or any kind of prescriber of medicine. I am a mother, caregiver and long term practitioner of Naturopathic remedies. Clindamycin is used to treat a number of bacterial infections. Of course you should see a physician to get your own prescription, if thats what you even need, because its not legal to take other peoples meds. Now that having been said, it sounds to me like you have some type of fungal infection. Could be yeast, jock itch, etc. I would try tea tree oil a few times a day on the affected area. Also fossil shell flour mixed with coconut oil to make a salve to put on it would definitely help kill any fungus or bacteria topically. But taking a few tbls of fossil shell flour daily destroys this stuff internally and protects you from future infections and overgrowth. Any kind of probiotics will help fight inside you. But if you have any STD, I can not say whether or not the FSF will help. You need medicine for that and its worth getting tested because of the infidelity issue. I hope this was helpful to you and may blessings be upon you!
From the symptoms it can be a fungal infection or intertrigo. Intertrigo most commonly occurs due to bacterial, viral or fungal infection. An intertrigo usually appears red and raw-looking, and may also itch, ooze, and be sore.
Please keep the area clean and apply some topical antiseptics. Also wear loose-fitting cotton clothing and use an antibacterial soap or mild soap like dove. Topical zinc oxide cream like Sudocrem, Desitin are very helpful(apply with a paper towel and not directly with hands).Application of mild steroid cream like dermacort also helps. For the itching please take some over the counter antihistaminic like Benadryl or Claritin. In case the symptoms persist then antifungals may be needed. Please consult a dermatologist in that case.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.