Baby won’t stop crying

Help!!

My son is 3 weeks and 3 days and he will not stop crying!! He was on similac formula till last weekend, then was on gerber formula because wic won’t pay for similac. I finally said heck with it last night when he wouldn’t stop crying till he puked sooo much till 1:30am! He’s been keeping me up all night and sleeps all day! Except today he’s been up since 6pm so hopefully I get some sleep but from the looks of it I will not be! We just tried gas drops tonight and then gave him a bath which I really liked! (Very relaxing) but now since I got him out again he’s been screaming! I really thought the gas drops and bath would help him! I’m so exhausted!! I also have a almost 3 year old daughter that will not let me nap and keeps me on my toes! I just want to give up! 😭😭😭