Because you are kicking ■■■! I was in the same boat a few years ago, felt like I needed to lose weight and get in shape. I started walking, partially to get more fit for martial arts classes, and have kept at it and at it and at it and it keeps going.
When I started saying "I need to do something, I'll walk around the neighborhood...", it was sort of weird but I just had to say "I'm going to do it and do it". I was inspired by a lady in our old neighborhood who'd do "laps" with her husband and walker. Rain/snow/ sleet, she was out there. I didn't ever walk up and say "way to go" but she was out there and, when I'd think, "nah, I'll just blow it off..." I'd remember her and head on out for a lap myself.
BG wise, I get a buzz when I'm running, a lot of times, I sort of "push it" to get home (or, maybe, I want to say "I'm DONE!"?) and my BG will drift up but the corrections are way over what they need to be and then I'll crash out. I've sort of got "habits" to work around that, a small bolus, take shower and eat something after more significant runs or do about 8-12G carbs/ 3 miles (185 lbs or so?) if I'm going farther. I "cheat" in that I have a CGM so, if I see it crashing out, I'll have something to eat. I bring stuff along but don't overdo it. I also figure some of the carbs are for "fuel" rather than BG. They usually have Gatorade at races, even 5K (although a lot of times, I can blow off carbs for a 5K, if I'm in the right spot beforehand...), so having a snack "en route" doesn't make you less sporty, it may make you more sporty? Keep it up!