Not an expert, but without having any clear idea of why you are on medication and what, I think few would dare direct your training.
However, there are the obvious suggestions of doing a lot more walking and cycling as ways of getting from a to b.
Core stablity, either Pilates or yoga are great ways to get control of your muscles. As someone very much older than you, I can say that it is very good for leaving you feeling very much younger and livelier.
Many many years ago from one as young as you suggests that you did school athletics. The heart rate of a teenager is no guide to what the 34 year old heart will do. There are a number of threads here about heart rates, and base training.
What does fitness mean to you? The ability to run a sub 4 marathon? A lean physique? The ability to carry a heavy pack and cover many miles over rough terrain? Getting off the meds?
There are all sorts of experts on here who might be able to advise. You might give them a little more to go on.