Multiple Sclerosis vs Lou Gehrig's?

I've been looking up muscular diseases and I found several similarities between the symptoms of MS and ALS (Lou Gehrig's). I know that with ALS, the affected person only has a few years to live and with MS it could just relapse every few years and they live much longer than someone with ALS. I know that major difference but as far as the symptoms and patho of it, what's the difference? The reason I ask is because I've been having a lot of weird problems with my muscles but it matches the symptoms of both MS and ALS. I know to get a proper diagnosis, I'd have to go to the doctor but just tell me what's the difference?