2 month shots

Kaelyn
My daughter got her 2 month shots 4 days ago and has been a wreck since then. Before the shots she was sleeping through the night and would take 4-5 oz at a time. Now she's up all night and will only eat 2-3 oz every 3 or 4 hours. I'm really worried about her. She's had 2 BM's in the last 4 days, one on day 1 after shots and one on day 2. On day 2 her poop was very thick and really hard for her to pass. I had to help her out quite a bit. She's super fussy and seems uncomfortable. I gave her 1 tsp of karo syrup in 1 oz of formula last night and gave her a warm bath which led to lots of farts but no poop :( she's formula fed. She already has trouble pooping and I think the shots made it worse. I'm at a loss and I don't know what to do to make her happy or even content. She's so fussy :(