I flush the toilet and have to hold the handle down until all the water flushes and then after I let the flap down, the tank will not fill up unless I twist the tower a little bit and water gushes out of the top of it... anyone know how to fix it?

I would go to homedepot and buy a new Fill Valve usually around $10 and install it off the instructions in the box.
http://www.homedepot.ca/webapp/wcs/s...k=P_PartNumber

If water is gushing out the top of the fill valve I agree to not mess with it and just replace. We frequently recommend a Fluidmaster 400a. Google