Hi Donna69, just wanted to offer my support as I am going through similar, however this is my first experience of thickened lining, hysteroscopy/biopsy etc...still waiting on results at present. It does affect mental health badly I found also.
Just wondering did they remove the polyp last time? Possible reason for bleeding maybe....I'm not sure. Other ladies on here will know more than me.
At least you've got an appointment with your dr tomorrow so hopefully they'll investigate quickly.
Let us know how it goes and remember a lot of us are going through the similar so hopefully that helps you