That chest area will be numb for a few weeks, because all the nerves were cut. After that a few days of pain, mostly where the V stitching is. The bones have like a dull ache. If you try stacking hay, there is sharp pain in that area, and shooting pains afterward.
Back when, the stitches were like fishing line, and had to be removed later. I removed my own stitches after the bleeding stopped, because I couldn't see paying $200 for them to do it. Now, they probably use those stitches that disolve.
I'm not sure why you (in general) can't walk further. Strength seems to be an issue, but I could be mistaken. It would seem that increased blood flow would help, but the facts wouldn't seem to support that. Standing up quickly is a bad idea, for several days. My lungs burned to breathe, but they didn't operate on your lungs, so you probably won't have that. Maybe blood loss is the problem. I remember tiring easily, and one leg seemed unsteady, so I had to lead with the other foot.