Clutch not engaging after replacing the clutch cable?

Every few days I had to adjust the clutch cable because it wasn't fully engaging. Adjusting it would fix the issue, and then the nut would back off or the cable was stretching, and it wouldn't work again. I replaced the cable and now, after adjusting many times, it won't engage properly. I replaced the clutch in 2018 so I don't think that's the issue. When I tighten it all the way in it is very hard to press and doesn't engage fully, and when it's less tightened, I have the same issue, but the pedal feels different. The only thing of note about the clutch cable change is that I wasn't able to get the grommet to seat fully into the firewall.