Bipolar and terrible memory

I have been diagnosed bipolar for 5 years now, and I have been through many many meds. There seems to be a constant factor, on meds or not. I have no memory! It seems I forget everything. Silly little things that have little affect on life, and major issues that totally screw my life up. I don't know what it is. \
I can leave the house with a list in my mind of 4 things to get at the corner store, and come home with 6, and only 2 of them were on the original list! I have to repeat things over and over to myself right up until the point where I actually do it, or it is no longer necessary to do them, or I will forget almost every time.
This has really started to have an impact on every day life, causing me to have to make two, sometimes three trips to the store to get what I need, or causing me to miss doctor's appointments just hours after I reminded my husband that I had to go. My children get very upset because I forget the days and times of their baseball practices and games, and they are late or don't get to even go sometimes.
If anyone else has had this problem, or does now I would love to know because at least I wouldn't feel as if I were developing altzheimer's at the age of 29. I would just feel better if I know that I was not the only one with this problem, and am curious if it is a symptom of the bipolar or a by-product of the medications.
Thank you in advance for your response, and well-wishes to all!