Thanks for all these additional details.
I am sorry to hear about your problems.
Well, from the description and after looking pictures, it sounds to be caused by fungus- tinea cruris. This is usually not serious and can be managed with medications.
The line of treatment is-
OTC anti fungal creams Canesten 1% cream ,it contains the active ingredient clotrimazole. This cream should be applied 2-3 times a day.
You should take tablet Claritin (loratadine) 10 mg at night daily for 10 days to reduce the itching.
You can take OTC Motrin 400mg twice a day. This will reduce inflammation of skin. You can Apply cream containing hydrocortisone.
You should wear loose fitting cotton undergarments, You should avoid sharing cloths, towels, wash cloths, and you should keep the groin areas completely dry after showering and before covering with clothes.
To be honest and from my clinical experience, i can say that your symptoms are not related with STD or any other serious issue. No need to get panic.
Most likely in one week, you would be free from symptoms.
This doesn't sound to be STD. No need to worry.
I hope this helps.
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