i hear ya with getting the motivation with a little one, its so much easier to say to yourself that its pointless to go for a walk because its nap time/ feed time or bubs to cranky (i know i have said the same thing for the past 15 months to) but once you get going i find i feel much better!
are you getting help for your PND and anxiety?
i have suffered from PND anxiety and post traumatic stress syndrome since bubs birth and i visit the Child and family health nurse once a month for a check up, i havent been medicated as yet as i am self treating with exercise and positive affirmations and it is working for me but i found i improved after i stopped expressing milk ever 3 hours for my daughter last month(she never breast fed(latching problems) and i chose for her not to have formula only breast milk for 14 months).
i found that i used food as a comfort with PND PTS and anxiety and my poor hubby thought he was doing the right thing buying me a family pack of chocolate and chips nearly every afteernoon after work, until he realised i was getting worse as i was in a cycle of eating to feel better but it would just make me feel worse in the long run!
i have actually since i stopped lactating started having a protien bar type thing from my gym called carbless i eat a coc fudge browie or strawberry cheesecake bar while watching tv before bed with a 750 ml bottle of water and that stops my sweet cravings and snacking at night!!!so that might be something for you to look into for late night tempations when bub has finally settled for the night!!!
if you need to talk im always around!!!