Heart conditions/blood pressure effecting exercise?

Graceraeg

I have a bicuspid aortic valve and often get dizzy, loss of vision, and nauseated during work outs. My doctor told me not to get my heart rate above 130. I am finding this impossible. Does anyone else suffer from heart defects or have very low blood pressure that effects your work outs? My blood pressure runs at about 92/54. On bad days it can be mid 80s/40s. Those days I have a hard time and don't exercise. Any tips advice?

Graceraeg

I have talked to my doctor multiple times. I'm looking for others with similar experience and how they cope with exercise.