my baby was like that also. she was very fussy and had lots of gas so she was uncomfortable. try some mylicon anti-gas medicine ck with Dr. first, but it is pretty harmless. I would really watch the overstimulation at this age. and also your stress as a new mom. I believe they can sense that. I used the baby bjorn a lot or you could use a sling. that makes them feel like they are in the womb. also keep down visitors. I got swaddlers from babies r us and that helped sooo much. They are very imature at this stage and it was very difficult to get her to rest at all. just hang in there. The less they sleep the more wound up they are.
I would try holding your baby and when she falls asleep place her in her crib and almost lie on her while you place her or him down. they feel like they are still being held. see if that works. It will get better. just hang in there. dod you get the book Solving you Problems by Tracy? It is GREAT. She has lots of tips in that book.