You cannot overcome creep by changing parts. The hammer and sear need to be mated to each other in regard to angle and depth of engagement. Any time a trigger group part is changed it affects the way the part interacts with several other parts. You can either put it back the way it was or have someone who understands 1911 trigger work to adjust the engagement and angles on the sear/hammer. And after that is done your thumb safety will probably not work anymore. "Drop in" trigger jobs are a crap shoot, it may make it better , it may make it worse, or it may cause serious problems. Be very careful as it is all too easy to end up with a gun that will double, triple, or go full auto if you don't know what you're doing.