I was diagnosed a few years ago and while (luckily) I tolerate the meds well and they make a big difference, the biggest improvement for me is - as a PP has mentioned - how I feel about myself.
I know now why I'm motivated in the way I am, or when something isn't motivating me - folding a mountain of washing that's been there 4 days because it causes a weird executive dysfunction error code in my head - I know now that adding some form of dopamine to the mix (in the case of my washing folding, Youtube or a podcast while I do it) works for me.
I know that the lists and post-its stuck on doors and calendars I've spent my entire life desperately hoping will fix me only to be abandoned later are non-negotiable tools I need to manage the issues with forgetting and organisation. Instead of being angry at myself that I've stopped using the beautiful Papier diary that was amazingly effective for 3 months and then giving up trying to be organised at all, I acknowledge my brain needs a new way to be stimulated and switch back to a little whiteboard in the kitchen, or phone alarms, or whatever, until that stops working.
Instead of "I should write things down because I'm a forgetful idiot" and then getting frustrated at myself, it's "I need to give myself tools to manage, write everything in this battered notebook you taken everywhere". Instead of "I hate socialising" it's "I like socialising when there aren't too many sensory inputs at once", and I have a happier relationship with how I spend time with other people. Instead of "I can never finish anything and I sit here for 5 hours staring at my laptop and just fail to do it anyway" I know the longer I sit at my laptop staring the worse it is, so I go and do something dopamine-giving instead and then break tasks into small, easily-ticked-off-for-the-tiny-reward-thrill blocks.
Understand how your mental reward/motivation system works and work with it: you'll feel far less of a failure for not being able to use one conventional method, and more able to move with your brain.