Dude, that sounds like shin splints... which is essentially an overuse injury. It makes sense since you're walking up hill your calves are being extended/lengthened more than usual.
One thing I found helpful was massaging my calves with a wine bottle while I'm sitting down... it hurts like crazy but in a good way. Try a bunch of different calf stretches as well. I had shin splints for a while, but I honestly haven't had them for years now.
Yeah I've had them for a long time but of course they're not a problem if I'm not doing anything. xD
I had this one dude in military training give me some kind of russian oil that I put on them and it helped so much when running, but then when the time came to shower it burned like crazy, lol.
I think I just need to ease into it and like you said do some stretches and massages until they get used to me dragging all this weight. With the weight going down it should eventually go away but it'll be quite a long process.
So yeah, it's not the first time but didn't wanna get into all that as it's a whole thing, lol.
I'll generally cramp or get really tight from the knees down doing anything more than a light jog, UNLESS I've spent 5/10 mins warming up.
Get the workout app, go for beginner lower body and use that as a warm up for the walks.
Okay cool... I wasn't sure if they were a brand new thing or not. Definitely not fun.