Are you saying that you feel you are limited to only the public health department or nothing? You can't just go to a walk-in urgent-care clinic or see a doctor? (If not, it seems a little bit of a double standard to get huffy that the guy didn't see a doctor -- jock itch can be cured with over-the-counter preparations and so his actions don't seem unreasonable, and he might be in the same boat as you are regarding going to a doctor.)
Anyway, if you are sure that the guy has jock itch and not an STD, you could assume that the guy gave you a fungal infection that is getting in the way of the tear healing completely. Jock itch is a tinea fungus. Here is from another website about jock itch and its cousins:
"Tinea infections are known by specific names, depending on the part of the body that is affected. The most common types of tinea include:
Athlete’s foot – tinea of the foot, known as tinea pedis
Jock itch – tinea of the groin, known as tinea cruris
Ringworm – tinea of the body, known as tinea corporis
Nail infection – tinea of the toe or finger nails, known as tinea unguium"
Again if you are sure it was jock itch, without access to medical help you might try taking care of it the way someone would try to take care of jock itch. There are over-the-counter preparations for tinea fungus infections, including Clotrimazole (Lotrimin) cream or lotion and Terbinafine (Lamisil) cream. Over-the-counter creams work on mild cases, and in your shoes I would sure try one. Only if your infection doesn't respond would you need an oral medication prescribed by a doctor.
If you are continuing to have sex with the same guy and his application of whatever cream he is using has not cured his jock itch, you should use condoms or not have sex with him. Though because of the nature of the tear, it sounds like you should should stop having sex (with anyone) until the tear has healed.
Good luck. If you haven't used an antifungal, probably just getting and using one on the tear will solve the problem.
Ouch. That's all I can say. I'd give it a maybe a couple of weeks with no sex to be honest. While hard to do, not impossible and hey, it will build up your desire for when you finally get back to it. but you need to heal. You want to be careful nothing gets infected as well. I would consider seeing a doctor as well. Lots of things are contagious from std's to skin issues. I'd definitely use condoms if you feel you can't forgo sex for a bit but a little tear will keep opening if it isn't allowed to rest and heal.