Oh, sorry to hear that you've been feeling uncomfortable with your body!
Walking seems fine, but If I were you, I'd try to combine it with running. This would allow your body to get used to the activity once again (I know you mentioned shin splints, but you'd be surprised of how fast the body can remember what it 'used to do') and also, great cardio to burn those calories :P Perhaps, you can start by walking 100m and running 100m for some kms, then you can change the progression as you start feeling better.
I'm a runner freak, so I would recommend any audiobook by Dean Karzanes, he's the ultramarathon weirdo that has run incredibly exhausting races (and has lived to talk about it, lol). I find it really motivating... it's either that or a good AC/DC dose to keep up the pace, lol.
Yeah that's a good suggestion, it's just that when I do get the shin splints it also makes walking difficult as the muscles get super hard and I need to take a few minutes to attempt to stretch them before I can walk normally again. Will have to try, my cardio is down the drain as well so will be happy if I can "powerwalk" without sounding like I just walked up the empire states stairs.