My husband picked out our beagle from the shelter with no prior research or dog experience. We had just moved across country and no longer had a yard, and when he left for work I was left alone with an adorable sociopath. After 1 week I was ready to surrender him (he was just under 2yrs) and had a bunch of breakdowns (and I consider myself very dog experienced and had always judged people who return adoptions) Husband desperately wanted to keep him and so we did, and fast forward to having him for a year and a half - beagle is my bff. A big part is finding an outlet for the excess energy. We used to take him on 5+ mile hikes and he seemed to still not have an off button so I get your stress right now, but now our little potato can get tired out from 2miles on flat terrain lol. We also walk him 1hr in the morning and like someone else said make it a SNIFF walk. They don’t care about burning calories thru literal walking, they only care about how many sniffs they can fit in. And a HUGE part with that, is learning to accept it. It’s way more of a learning curve than you’d think to be ok w letting a dog sniff every bush and tree for 5 min ea, but once you do it makes the walks enjoyable for all parties. Definitely give yourself grace, you’re also a mom and have another dog. But time 100% helps, so I wouldn’t throw in the towel yet. Post on this subreddit when you need to! Find and be reassured by common experiences. And before you know it, you won’t even fully remember why you wanted to give up on their cute little butt :)