Hey y'all I need help/ any of y'all experience this?

I recently got diagnosed with inappropriate sinus tachycardia just about 2 months ago now, issue being that I have an already low resting heart rate

50-55 bpm usually when laying and down to 35-40 when sleeping

I'm on propranolol now and sitting up my heart rate is regularly at around 50-55

I asked my doctor to lower my dose and all he said is that if it's making my heart rate too low, I should just stop taking it or take it as needed .....

Problem being is that you can't just stop taking propranolol, + I had episodes of severe heart palpitations, clamminess, low blood oxygen, shaking, thirst, fear etc

On this medication I haven't had a single one, I can't go back to how it was before, I really think I would've died

Blood pressure spiking to 195/110 heart to 165 bpm when laying down then going down to 25-30 bpm over and over again, it was awful,

Do I just kinda deal with it and keep taking it until I can see a new doctor? I don't really have any specific symptoms with my new heart rate but it still concerns me and my cardiologist did say to take it only as needed now, even though that would be every day technically + he only gave me extended release at 60 mg propranolol