We saw a long white worm looking creature crawl out of

If the worm looked like spaghetti, then this is roundworm. The treatment for this is a drug called pyrantel pamoate. Most pet stores will have this medication as well as dosing information based on body weight.
If the worm was flat, squarish, and segmented, then this is tapeworm. The treatment for this is a drug called praziquantel. Again, I believe most pet stores carry this medication. Tapeworms are often spread by fleas so make sure to treat him for that as well.
The best thing to do is hang onto the little fella (the worm) and bring it in to your vet's office in the morning. They can identify it for you and get you appropriate medication. Dropping off a stool sample is also a good idea, as they can examine it to see if there are any other parasites present.
As far as him sleeping a lot, it probably isn't related to the intestinal parasites. It may be the warm weather. If he is otherwise doing well (eating, drinking, playing, no vomiting or diarrhea), then it's ok to monitor him and call your vet if you see further problems.