Flying through the air re: puppy training techniques

Here’s my problem. About a week ago we were having one of our walks. Within
what now seems like a split second, a man with a dog jogged within sight. I
didn’t see Garth running to to greet them. I had the leash around my wrist.
When he got to the end of the leash (still not very close to the jogger) I
went flying through the air and did a very hard belly flop on the hard
ground. I may even have passed out for a few seconds; the next thing I knew
Garth was sitting near me and I was in extraordinary pain all around my
midsection and couldn’t move for a few minutes. Fortunately nothing was
broken and I managed to make my way back home. I guess my ribs are pretty
bruised since it’s still painful to move, but my biggest concern is that I
haven’t taken Garth out for a walk for a week (he has ample time in our
backyard with his bf our other poodle). And, I don’t know whether I can use
the 20 foot leash he enjoys so much again. As alert as I try to be, it seems
impossible to be 100%. I am hoping y’all have some advice for me so that
when i feel better we can resume our long-leash walks. By the way, there are
NO dog parks anywhere near me that I can take him to instead.