My mum had manic depression

My mum had manic depression about 4 years ago after she and my dad separated. This made our relationship difficult at the time as there was a role reversal as I was basically her Mum for a few years looking after her and she was in and out of hospital. Since then she has been well and managed her depression by medication. However she tends to make my sister and I feel bad about her being on her own which makes us feel guilty and she has recently been told she has to come off her medication due to it effecting her heart which has brought me anxiety as Iā€™m worried she is going to have another break down after she is off it. She is always negative and it is incredibly hard to deal with. It makes me very frustrated, anxious and guilty for having a life of my own.