I recommend that you get up and walk around your house whenever you go to the bathroom. The more you walk, the less shoulder pain you will have. As soon as you're up to it, go outside for a walk. Don't overdo it...just slowly...but the more you walk (at least in my experience) the better your shoulder will feel.
You've had major surgery at the center of your chest, so that pain is very understandable. I expect you've seen this, but just in case, it might help to read through my early recovery journal. You'll see that your experiences are common.
Be sure to take the pain medication you've been given. As soon as the pain subsides a bit, you might want to switch to liquid Tylenol, since it's a little easier on the stomach and won't make you feel groggy. It's a good idea to take the narcotic pain meds at bedtime even after you stop during the day. They'll help you sleep. Pain always seems worse at night.
Be sure to keep a handle on your nausea. You won't want to retch or vomit at this early stage. I assume that your surgeon sent you home with a nausea med script. If not, call and ask for one to be ordered. You (like all of us who are wrapped) should always have nausea meds handy.
Words of wisdom by Eckhart Tolle:
"Whatever you fight, you strengthen, and what you resist, persists.”
“Worry pretends to be necessary but serves no useful purpose”
“Accept - then act. Whatever the present moment contains, accept it as if you had chosen it. Always work with it, not against it.”