my oven was taking a long time to heat up and now it won't even come on to preheat at all. broil works fine but not the bottom in the main compartment. i'd like to try and fix this myself.

Derek, this is a pretty straightforward repair and sounds like your ignitor has failed. It may have held on for awhile when it was taking a long time to heat up but most likely wasn’t maintaining the setting even then. I’ll attach a link below for the part you’ll need: 5303935066, and a video as well so you get diagnose this properly and get it taken care of yourself. Should you need any further help, let us know. Good luck!