当初我还被妳念(念叨)得跟罪人似的!
当初: in the first place, at the beginning
念叨:if someone 念叨, they keep talking about something that makes you feel embarrassed or upset
So this sentence literally means: You blamed me for this at the beginning as if i had been guilty.
We would say this when we thought someone had done something wrong, but eventually he/she was proved wronged.