Cheer up Ace!
There's no reason to give up, as someone else pointed out, it's not your fault. Intestinal worms are brought home, they don't just appear out of nowhere. If it makes you feel any better, here is my story. In January I brought home a couple of ladies for my male Zebra Chilumba (he already had one female). A couple weeks later I started having problems with my fish. So I would treat, they would get healthy and then they would be fine for a week or so. Then they would fall sick again. This went on for a while, a couple months and I was completely puzzled. I started to suspect something was seriously wrong, however, I was not fortunate enough to have worms dangling out of the bums. It took me countless days, and countless hours under the microscope searching hundreds of fecal slides until I finally found the nematodes, as these were the kind that stay inside and only release eggs in the feces (which blend in nicely with fecal matter). Anyways, they were treated and the worms are gone, but their immune systems are still not quite up to par yet, and have been dealing with minor problems, little bit of tail rot and fungus. I lost the oldest female late last night
but I knew this was going to happen as she's been in the hospital tank since January and her recovery was very poor. The other two ladies are looking good, but it's still gonna take a bit of work. Somehow, the male managed to go through this whole ordeal with nothing wrong, which I guess is the brighter side of it all.
We all run in to problems now and again, but the rewards outweigh the occassional downfalls. Keep it up, and as you learn more, you will become more confident in your fish keeping abilities, and will be able to spot potential problems early and be able to deal with them accordingly. It's a wonderful hobby and I'm sure in time, you will start to suffer from MTS (multi-tank syndrome)
And besides, if you gave up now, there would be no reason to visit this forum, and what about all the wonderful helpfull people here you'd be leaving behind?