Hi! Truly sympathise with you. As mummies & daddies, we all have to go through this untold phase of sleepless nights, worries, ear-aching cries (or screams), teenage mood swings, slam doors etc. I agree with Mrs Boris that babies need to be held alot. But when you're alone at home with chores to do, you can't be holding on to him/her at 5 months plus on a baby sling (unless very young) always. There are times when one needs to just "switch off" for our sanity sake.
My boy is 8 month (going 9 in 2 days) and he cries whenever he can't see us nearby, wants to sleep, hungry or just plain cranky. He used to cry due to colic or wanting attention. But one day both of us just had it and we left him to cry for 45 mins in his bed!! Then the next day he cried for 30, the following 15 and now just 5 or not at all. What we did was cuddle him, tell him stories and hum (can't sing!!

) him to sleep. But he wakes up within mins when we tried to sneek out of the room!!! So now we still hum, tell him stories and cuddle him but explain to him why he needs to sleep (even though he can't seem to understand us but its still communicating with him right?).
He used to want to eat in the middle of the night from 1th till 7th month old. But eversince we start solids at, he seems to be holding well from 9pm till 7am (feeding time between 6:30pm to 7pm). May be you can try to feed your baby a little later than normal time? Or may be your little one is going through the growth spurt phase, which might explain the mid-night feedings?
Things WILL GET BETTER!