I need some serious help...with my 8 month?

hi..if theres any mom out there that can give me an opinion about how to teach my son not to want to be with me 24/7...im a single mom and dont have any family in canada..so the only person he sees is me...i talked to other moms and they tell me let him cry it out..if u have changedd him gave him his bottle and everyhting else and he still crys hes just spoiled...i dont know wat to do i tried livin him there to cry watchin carttooons..he got so red and cried up to the point that he was shoking and makinn him self puke...i dont know wat to do i feel like such a bad mom, for leting him cry,,but theres things i need to get done around my home and cant..it has got so bad that i now have tendonytis on my arm and it hurts when i pick up anything....does anyone have advise or if they went tru this..thanks