I'm wondering if one physician placed you on these medications, more than one, and if more than one, if each physician is aware of what the other physicians prescribed?
In addition, are all these prescriptions filled at the same pharmacy? Pharmacies are supposed to use a system that checks for interactions between medications.
It is important for any and all doctors prescribing medication to know what other medications, including over-the-counter medications, supplements, vitamins, and herbs, and illegal drugs (not saying this applies) that you are taking. Then, rather than relying on the best intentions of doctors, as they, too, are only human, you need to get the prescriptions filled at the same pharmacy, and speak with the pharmacist there about your medications (all of them), supplements, vitamins, herbs, etc. You can also go to a pharmacy where you only have a few of your prescriptions filled and tell them what other medications and supplements you are taking, they can check.
Pharmacists in the U.S. used to be registered pharmacists RPh, now they are Pharm-D (sounds agricultural) which is a Doctorate in Pharmacy. Pharmacists (especially good ones) have more knowledge, IMHO, of the side effects and interactions between medications than doctors.
That said, in my opinion, 55-68 resting heart rate is normal, depending on conditioning, just be sure it's regular. Ectopic beats, such as PVCs, can cause compensatory pauses, these make the heart rate appear slower, but the rate would not be regular. The presence of PVCs, if you have any, are usually not a cause for concern, but asking your doctor for advice would be advised.
76 - 86 also appears normal. If you are short of breath, dizzy, lightheaded, these may be more significant indicators than rate by itself. Walking around is subjective, so it's hard to guess just how active you are.
You can't be diagnosed on a forum, you need to see your doctor to best answer your questions. I'm neither a doctor or pharmacist, just, like so many other people on this forum, offering stories of our own experiences.
The best way to assure your continued health is proactively, reducing your weight, eating the right foods, getting modest amounts of physician approved exercise. Medications are great for delaying problems, or improving the quality of life for people with conditions, but if proper care of ourselves can keep us healthy without them, we'd be better off. Years ago, after a night of drinking, I totalled a motorcycle. Though wearing a helmet, I bounced off the street quite hard. Within a year or so of this, I developed a condition that went undiagnosed for over 15 years. I developed seizures. "If only I had" it to do over again, and not drank the night before I wrecked, or not drank at all, or not rode motorcycles (at least not wrecked them) my life would be significantly different than it is today, I wouldn't be on a medication I don't need, I can only guess how that would have improved my life.
"If only I had". You're still at that point, you can make the right decisions. Talk with your doctor, ask for a review of your medications, overall health, and concerns, appreciate that your life is just really starting.