It may be that you need to be on an antifungal medication for much longer that you have been taking it for.
If you do not have a follow up appointment with your dermatologist, make an appointment to see your doctor. He can take a swab of your penis to get it analysed at the laboratory to identify any fungus, yeast or bacteria.
Eumosone cream (Clobetasol Butyrate) is a very potent corticosteroid that is used in short-term treatment of various inflammatory skin conditions. Corticosteroid needs to be used with caution and as directed as it can thin the skin. As this cream has not helped, it may not be the right cream for your problem.
You may try an antifungal cream or spray that the doctor can prescribe for you (depending on the results of your swab as you may need an antifungal that is also an antibacterial). You can also purchase antifungal creams from the pharmacy without a prescription and your pharmacist will be able to help you with that. In the UK Canesten can be purchased, but the antifungal may come under a different name in your country, so do ask the pharmacist.
Like alex0306 says, only use products that are suitable for sensitive skin. Also those that have the pH level like our skin, baby washes will be fine. Don't use any perfumed soaps, bath or shower gels. They are very drying to the skin. You can also purchase without a prescription, emollients to use instead of soap.
Wear cotton underwear as these help your skin to breathe and not sweat as much as the manmade fibre fabrics.
As a home remedy, you can apply natural set yogurt to your cleaned and gently dried penis. You can use it for as long as you need to without having any side effects.
Be aware that fungal infections can also be spread by sexual contact, so your partner may also need to be treated, even if they do not have any symptoms, your doctor will advise you about that.
If you use normal latex condoms, you may have developed an allergy to the latex. You can these days purchase latex free condoms and these may be better for you.
If you do get fungal infections frequently, it would be a good idea to get checked out for any signs of diabetes. Fungus loves sweet, so having a good healthy and well balanced diet will also help as well as controlling sugar levels if you do have diabetes.
Wishing you a speedy recovery.
Try using a sensitive skin cleanser instead of soap. Be sure to shower every day, and make sure your skin is dry before you dress afterward. Wear all-cotton underwear and don't wear tight trousers. A penis health cream like Man1 Man Oil, which has a natural moisturizer, might also help.