T.M.
You didnt say how old he is, so I'm not sure what stage you are in.
It sounds like YOU might have separation anxiety. It is okay to put your baby down for a few so you can get some necessary things done, if they cry, they cry.... They really don't know what else to do at times. It's always good to place them somewhere where they can see movement, it mesmerizes them and distracts them (why mobiles above the crib were invented). Kids need to see movement, feel movement..... get creative.
ETA: Let him crawl around after you while you are busy. he'll soon learn that the crying part is an unnecessary add on. Kids sleep a LOT better if they get a LOT of physical exercise during the day. The same goes for adults.