When you get a "fish" smell, this is usually because of bacteria.
You may have a bacterial and/or fungal infection.
You do need to make an appointment to see your doctor. Doctor may know what it is and prescribe the appropriate medication/s or may do a swab and send that to the laboratory to be analysed.
For the cracking of the skin, you need the right type of moisture for it, and your doctor may also prescribe an emollient for you to use instead of soap, or a spray emollient.
Do NOT use normal soap, bath or shower gels. Only use non perfumed soap, soap with the same pH level as our skin, baby washes may be fine, or just plain water.
Don't wear manmade fabric pants, wear cotton ones. These help your skin to breathe.
Use non biological washing detergents and if you do use fabric softeners, use the ones that are OK for delicate skins.
Only use latex free condoms, as you may be getting an allergy and irritation from latex.
Like Dalubaba says, don't both with self medicating, you need to see your doctor to get the appropriate treatment for the condition that you have.
You are doing the right thing by abstaining from sex. Wait until you are well healed.
Make an urgent appointment to see your doctor.
Let us know how you get on.
Wishing you a speedy recovery.
Real advice you can get from is a doctor who knows about infecting agents, medicines and the nature of your problem.Do not try random creams. Please be careful as this is a delicate situation.