Seth,
It definitely does get better after a while of doing it continually...it becomes a routine and a habit. But definitely warm up before and cool down after and you shall feel much better.
You have to ask yourself one question: Where will I be in five or six months from today?. Now, you have two choices:
The First choice is to keep sitting on the couch and give up on exercise.
The second Choice is to push yourself to exercise and increase it a bit each time until it becomes a part of your routine.
Now, look at yourself afte the five or six months (not today, not tomorrow)...look at the results of each choice you made and compare them.
You shall definitely feel fit and trim and happy and healthy with good circulation of blood all over your body (2nd choice); or
if you chose the first one, you shall be mooooooooore sluggggggish and laaaaaaaazier, more bored with lots of guilty feeling and confusion from not helping yourself feel better.
Anytime you want first choice, medidate on imagining yourself full of energy, playing with your son and enjoying each other, and enjoying the energetic feeling and the better health you shall achieve. I think this should be a great incentive to push you to exercise and be as healthy as you can for your son and wife and for yourself!
Good luck and keep us posted.