It sounds like a really tough 6 years for you so it is super exciting you have found a wonderful woman whom you are keen to bring out your erotic self and engage in some fabulous sexual experiences.
I can absolutely understand your concerns and the anxiety you must be feeling about using anything to help your erection that may impact your health. Making a decision in regards to taking medications against your doctor’s advice would cause you stress which, as we know, can have the opposite effect and make having an erection difficult.
The ideal outcome would be to find a solution that allows you to engage in a full, erotic and satisfying sexual relationship, with the approval from your doctor. I would suggest having an honest conversation with your doctor about how important it is to you to have an erection and engage in sex, and ask them about all the options available. They will be able to advise on other possible medications, penile injections, penis pumps and rings or penile implants.
A great exercise you can do on your own that may help maintain an erection is pelvic floor exercises and something I try and do at least once a day. And remember, your penis is just one part of sex, take the time to explore your playful erotic self, the other areas of your body that sizzle when touched and the delight in turning your partner on in multiple ways.