I need tips on dealing with "terrible 2's" twin boys. HELP!?

Hi! I am 22 with twin boys who are 2 and 4 months. They are really sweet, but recently snapped into mive misbehaving modes. They are constantly throwing toys and when i constantly ask them not to they stick their tongues out and spit i slap their hands and tell them no thats not nice. They still dont listen they have the worst tantrums and are extremely impatient. And im loosing my patients. Im usually good with letting things not bother me but they are driving me nuts. I use time out at dinner time because they refuse to eat most of the time and just throw the food on the floor. Once i use time out they eat but that seems to be he only time its effective. I them whwn they really miabehave but i try to shy away from that to a last resort. I really need help opinions anything....im a stay at home mom and i can only take so much. Thank you.