Wow. What a loaded question. At the end of treatment you DO feel like a lost puppy, and that is where so many here will tell you "Welcome to Survivorhood". It is not for the faint of heart. In Survivorhood you fast realize that "normal" is (and always was) just a cycle on your washing machine.
For the first while post treatment you sleep. Your body goes about the business of repairing itself as well as it can. You eventually get used to things you never thought you would like having to go back to the house to get your teeth because you don't wear a denture all the time anymore! You work on your sense of humour and you work on other parts of "YOU" that maybe weren't paying attention to the world in the manner you will from this point on.
You will spend some time worrying. For some of us it takes up far more time than it should - but you worry about scheduled tests, worry about appointments, worry about results, worry about friends.
What you do - I hope - is really learn to appreciate the "NOW" ness of your life. It really is all any of us have

Be well.
Donna