Issues after Cross Progression is activated on your account? Check here first!

I played on my account for like a month after the cross progresion and today after the new ranked split and some uptades I got a notification that the cross progression is here and i was level 1 after I restarted my game and  I had lost all my season 20 progression and was back on the season start. I lost all my coins and skins, and levels that i earned in the season 20, and packs, and the new flatline's skin missions. Please help me fix it because i lost a lot after this cross progression. I will really appreciate for your help.