Ugh, I know exactly how that feels! Last year, I missed a payment by just a few hours, and the interest hike felt like a punishment. It took me months to get back on track, and the stress was awful. Honestly, these companies make it so easy to fall behind. I remember calling them, and they were no help at all.
Setting up text alerts a week before the due date saved me from that. Most banks offer this for free, but you have to dig into the settings to find it. I once got charged because my payment date fell on a holiday, and the bank processed it late. Now I always pay three days early to avoid any surprises.