Very loud fan after battery replacement

I replaced the battery for my Mac last night and let it charge for a several hours afterward as directed. When I first tried to power it on nothing happened, but after holding down the power button enough times it eventually turned on. It seemed to be working fine with no lagging or anything except the fan was on really loud and wouldn't turn off. I unplugged it with the display open to see what would happen and it just shut off and wouldn't turn on again until this morning. Now it seems to be functioning again but the fan is still really loud even though the device isn't overheating. I also can't see the battery icon in the upper corner so I downloaded coconutbattery and all the numbers (current charge, charge capacity, etc.) say 0. Looking at other posts on here it sounds like maybe I messed up the trackpad connection to the logic board? Or could this indicate that I damaged the logic board itself somehow? Thank you!

edit: added coconutbattery info