There are rare moments when you really feel like you are making a difference. I've had doctors genuinely express appreciation for explaining new information to them. Staff members who were grateful for help in getting a patient's medication approved. And patients who, hearing what medication I was supporting, pulled me aside to relate how much that medication had helped them.
Unfortunately those moments are few and far between.
With the pressure to hit calls/day and other nonsense metrics, all you can do is run from office to office, get your sample signature (or a signature for coffee or whatever), and move on. It's all a numbers game now. Quantity over quality.
Do your part, play the game. The good news is that the work/life balance is better than most other jobs. Your sense of self worth and self respect will take a big hit, but that's not unique to this job either.
And remember, there are many doctors who are barely getting by. Think about that, next time a doctor treats you poorly. Medicine isn't what it used to be.