Cat won't stop grooming himself! He's losing hair!

My cat wafer is a orange longhair cat. When we got him from the humane society, he was being treated for hair loss, due to the amount of fleas on him (at least that is what the vet said). She said his skin was red and he was losing hair, he would get better if we just gave him the rest of his pills. The hair loss was on his underbelly. Well now, 4 months later, he is grooming himself every 10 minutes, licking and itching, and it is giving him red sores all over. And at the start of his tail, he is having major hair loss. He has hair loss wherever he is itching, but you can really tell by his tail. I don't know what to do, because I don't have the money to take him to the vet, I just paid $1000 out of pocket to get his urinary blockage taken care off, and now this is coming up. Is there anything I could buy at a pet store that would stop him from itching? I haven't seen any fleas on him, and my dog barely has any fleas also. He is also starting to swat at us more often, and going after my dog. Is this because he's uncomfortable or in pain? Can you guys give me any advice? Thank you so much!

I do not have any personal experience dealing with flea's.  I am going to post a link to an article about flea's that might be helpful to you.  The article mentions getting medicine from your vet but I just did a little research and it looks like the treatments can be purchased online.  I used Amazon.com to check.

http://www.thecatsite.com/a/cat-fleas

http://www.thecatsite.com/a/homemade-flea-remedies

Do not use any of the Hartz brand flea collars or treatments you find in pet stores they are really not safe.  I am not sure why stores continue to carry them.

I bathe my cats with dawn dish soap and that kills 100% of the fleas on their body. I've used oatmeal baths on dogs for sensitive skin you could try that

You can buy Advantage II or Frontline Plus over the counter at Petco and Petsmart, they even sell Frontline at Walmart now.  Most of them work very quickly too, at least they get some relief in a few days.   If you don't have a flea preventative program for Wafer you definitely need to begin there.  Revolution is available from the vet, it is pricey, but it is the best I've used--I can't use it anymore since mine had a reaction, so now I use the Advantage II. 

If he keeps getting flea infestations after your get rid of this round, you also need to treat your home/yard.  Fleas will make him ill in so many ways!  Not to mention, you will have a nightmare problem if your house gets infested.  It is a process to get rid of them, not just a spray and forget it kind of situation.

I'd call the vet's and ask about medication for itching if he is truly that bad--ask about antihistamine treatment for itching.  There are several medications that will help with the itching, my cat takes a simple allergy med daily due to other allergies that were causing his fur to thin and him to be itchy, it has helped tremendously--and he has severe reactions to fleas.  It's not a steroid, it's a for-human-use antihistamine I buy over the counter, but I had to get the vet to approve me giving it to him and provide me the correct dosage.

I'd try what @mckaytr91  said as well, if he will let you bathe him.  I've alleviated Wurp's itching before simply by bathing him from the shoulders down in the sink with lukewarm water and the blue Dawn dish soap.  I've only done it a few times because it dries his skin out so bad, but it did help him get relief!!  He acted so relieved that he could sleep and not be itching, licking, scratching, washing. The Dawn bath will kill fleas, but you will still have to stop the source of the fleas or he will end up in the same situation again.