Masive SR loss after 1 single match

I played 1 game in overwatch as a tank and I lost more than 100 SR. I dont know why, i didnt leave the game and I didnt play bad either. The match code is ‘‘DAJNXJ’’ Please help. Greetings.

After your initial placement matches on an account, gains/losses start between 100-150 SR, and decrease over the next 15 matches to normal levels. It’s adjusting you to your proper rank.