Are my mom's health complications due to my bad caregiving?

Not Likely: If you care about your mother then you could not provide bad caregiving. There may be areas in which you can improve so check with your doctor or hers and get suggestions where you can improve.

Caregiving: There isn't enough available information to know if the quality of caregiving contributed to your mother's health problems. We don't know what her complications are & we don't really have any way to judge how you provided care.