Thanks for using DoctorSpring.com for your query.
So the current issues you are facing are fatigue and severe premature ejaculation.
What I noticed from your history is you have been on Zoloft and Adderall since a long time, and that itself can lead to premature ejaculation and other sexual problems like loss of sexual interest and impotence in some rare cases.
I will recommend you do think about some other anti depressants as you're fairly young and the medicines has already caused severe PE. You can do kegel exercises to strengthen your perineal muscles. Apart from this, I agree with your physician and suggest Propranolol for the tachycardia. I will suggest you discuss the option of propranolol and venlafaxine as they act well together without any interactions and does not cause fatigue.
Feel free to discuss further,