I cant handle heavy work liek that, I thought I could, but my knees and back starts hurting like HELL and I cant sleep because of it.
So im gonna have to works as a salesman or some shit like that
right now, Im closing in on working with children though, always been great with kids.
Kids and moms 
Honestly, bro.. a week or two into heavy manual labor and you won't be phased at all. Just smoke some weed to loosen up your muscles, take fish oils and you'll be good to go. Get your entourage of fine Swedish hoes to give you rub and tugs and stop making excuses.

Sales can be pretty good. It depends on what you're selling, who you're selling it for and who you're selling it to. If you're working for a good company with a good customer base then it can be great, otherwise it can be hell.
I work for a cable company and when I did sales for a while, I made a lot of cash. If you're working for a good company you can have lack luster sales skills like I did. It just comes down to having a good product and positioning the features and benefits. It's just hard to stay motivated through all the repetition.