Transmisssion Help

Last weekend my fuel pump went out on my 99 2dr 4wd tahoe. No problem pulled the tank and replaced it my self. Then after starting it a couple of time to make sure it worked i left it for a couple of days. Yeasterday i was out driving it and it was having a hard time making up its mind on what gear to shift into? Never had any problem before this with the transmission, and i have owned it for 3 years. Then today it will not do anything but shift from park to nutreal and that is it. I heard that if i change my transmission fillter that might fix it? It was towed to my house after my fuel pump went out woud that casue anything or me changing my fuel pump have anything to do with it? Thanks in advanced.