I'm so glad you had a chance to air the cobwebs out and have a lovely walk! It's always so refreshing and gives some space to think about things.
I think what you're feeling about being a perfectionist and beating yourself up about things is something most of us do... On one of our LL sessions years ago our LL counsellor asked us to really think about what our internal monologue sounds like; and then apply it. Would we speak like that to our friend? Most probably not. It made me realise how much I hated myself, when actually, I should be my own best friend in a way? (LOL sounds so weird). It IS ok to fail sometimes - because we're meant to learn from our mistakes. There is nothing wrong with stumbling every once in a while.
I would encourage you to stay off the medication, in my experience it did more harm than good... In my case medication didn't actually make depression go away, I knew it was there, but the chemicals FORCED a false elation. More of a curse than a cure to be honest!
Doing what you are doing now - REALLY looking at your issues, REALLY working through on your own - is a LONG-TERM cure. The anti depressants may mask the feelings for a little while, but the core issue will remain unresolved.
You're doing great Slim, keep working on it.
There are no hard and fast answers to any of this... just take it one day at a time.
x