I too have a child with learning disabilities and I have home schooled. In fact, the only reason we don't home school now is because my daughter, the child with LD's (CAPD, Dislexia, & ASD with ADHD tendencies) gets much better instruction than I could ever offer at her school. I don't know how far you are from a Summit Academy, but they are WONDERFUL schools. My daughter has excelled and become an entirely new kid since enrolling there. The schools accept anyone who is a resident in the State of Ohio who is diagnosed with ADD/ADHD or other learning disabilities, so your son would be eligible. Many families drive their children to the school, some well over an hour. That choice would be a personal one but I highly suggest looking into the school. You can find more information by visiting www.summitacademies.com Click on Our Schools, Campus Locations to see the schools closest to you and there are several other links for great recourses and information about the school.
Home schooling is difficult no matter how you slice it. You have to juggle not only being mom, but teacher too. Setting those boundaries and maintaining them is a tough job, only complicated by your son's ADHD and disinterest in applying himself. That could be due to his history in education. Maybe he just feels as if it's "not worth it" for him to apply himself because of his difficulties, how he's been handled in schools in the past, etc. There are so many things that could apply here. Finding the right techniques are key and I can say from my own experience with home schooling, standard public school at home situations are extremely difficult for kids with LD's, attention based ones are even worse. Curriculum's that focuses on multi-sensory learning is the BEST for kids like this. It uses all parts of the brain, it doesn't get as boring, etc. I used KONOS, a Christian (but easily used as a non-christian) curriculum, that utilizes unit studies and multi-sensory education. I found it very easy and MUCH cheaper than any other program. Learning to Read & Write is also an awesome English/Lit/Phonics program for pre K through college level. It's also very economical, being that it costs less than $50 and is a universal program through college level. Both curriculum's are easy to understand, easy to use, and easy to build upon if you want to come up with your own lessons as well. For math, I used Saxon math. It was the best for my kids and used multi-sensory as well. It does take a lot of time to home school using curriculum that isn't laid out by the school system, but it's well worth it. It sounds like you're very busy with school but I don't see why, with proper planning, you couldn't easily use these, or other, programs if you continued home schooling and I believe that changing the approach would be a benefit for you as well as your son. There are home schooling groups for ADHD home schoolers also, you may want to look into them. I know it's rough sometimes! Keep your chin up, it'll all be smooth sailing once you find the nitch that fits both of you.
As for his ADHD, there's lots of help out there. CHADD is a great resource and there are a lot of online and other groups and information collections. We use the Fiengold Diet and it's worked wonders. Also working with her doctors and teachers with suggestions on environmental adjustments, etc. My daughter doesn't take medication at all and to be honest, you'd never know she has this "disorder" now that we've implemented the suggestions and the diet, as well as found our own little things that work. I know many children still need meds even with these changes but many times at a lower dosage. Having a kid with LD's can be an adventure, a frustrating one sometimes, but still a positive one. There's lots of help and support out there, don't be afraid to utilize it.