Went through something similar years back with a semaglutide product. But it hit only after I paused it. Used to have very regular cycles too. Then started the tablet version a while later. A few months in, cycles stopped completely and I panicked and told my doctor I was quitting. Within about a week, everything started up again. Ended up with seven straight weeks of periods. Genuinely miserable stretch. No pain or anything else though, just constant bleeding.
So once I restarted the tablets, I saw a gynecologist and got put on a hormone medication, worked out the dosing and timing with them. It was specifically meant to induce regular cycles. Stayed on it for a good long stretch, mostly out of anxiety even though things had stabilized, and some months later after switching medications, my endocrinologist convinced me to try going without it and see how things went, with the option to restart anytime. Cycles have stayed on track ever since without needing it.
So maybe look into something similar, or another birth control option, whether pills, an implant, or an IUD. Personally get bad cystic acne from one type, so ended up switching over to a different hormone-based treatment instead.