Sounds like you're on track. The drains heal, sometimes quickly, sometimes not. As long as the wounds are clean and healthy-looking, just care for them and protect them. Let nature take its course.
Chest muscles are a bit more difficult to judge. They will heal, for all intents and purposes, fairly quickly. But. . . they may feel "funny" and hurt a bit for quite a long time. Before my surgery I was a self-admitted gym rat. I did a lot of different exercises, including push-ups. At the time of my surgery I was doing 3 sets of 60 push-ups daily. After surgery, I could not stand to do even one - for quite a while. It wasn't until almost 6 months after surgery that I was able to tolerate any push-ups, and even then, I had to start all over again with shorter sets. I'm really not back to where I was, but not because of my chest muscles. This time, as I got older (now 68), the bit of arthritis I have in my shoulders has acted up, so I have to do shorter sets of push-ups, and fewer total reps, to avoid pain that can last through the day.
I would say that by 9 to 12 months, my chest muscles were fully recovered. Don't rush it, things take a while but they will return to normal.
