why am i having problems starting my car?

back in may of 2014 my son hooked my battery up wrong. i replaced two fuses, one
15 amp small one n one 50 amp main one. it ran fine for awhile and then the
distributor had to b replaced. it ran fine again and then for the last month it has been
hard to stsrt on its own most of the time i will pop start it since it is manual. the last
few times starting it, it acted like it wasnt fully charged and after a minute it came
back as full charge, it will even flicker the lights while driving down the road at night.
what do u think is the problem.