Sounds like you have the sear/trigger return/disconnector/grip safety leaf spring spring in incorrectly.
That will cause every issue you have just described. It's a bit tricky at first but once you know how it fits in there and how to install the mainspring housing you'll get the hang of it quick enough.
Pull the Mainspring housing and make sure that each finger of the leaf spring is engaging the correct component.
The finger on the far right is the grip safety return section.
The middle section pressing on the bottom, angled portion of the disconnector.
The left section engages the bottom, flat portion of the seat with the "little dog leg" riding off to the left side of the sear.
Like so: (
pic courtesy of 1911.org )
Make sure that the 90 degree bend at the very bottom of the spring ( not pictured but where the spring rides against the frame ) locks into the small slot in the frame, and make sure it stays put as you re-assemble.
Too, make sure that before you slide the Mainspring Housing into place that you lower the hammer.