This is gonna sound trite, but ... focus on the good. Dive into that. "... an improvement in energy and motivation..." is an opportunity to do just about anything. Start running. Hone a craft. Grab on to that positive motion and do something with it. Thinking about what you have "lost" or have been "losing" over the past six months is mostly FOMO, and if you fill your time up with your newfound energy and motivation, there won't be time/focus to dwell on the past. I wish the best for you.
Maybe FOMO isn't the right way to say it... but we forget things every day, and it doesn't cause us stress. When you said you were having memory lapses, I read into that, "I am forgetting stuff, and that's bad, and I'm beating myself up about it"... which admittedly might be the wrong interpretation, but I thought a "hey, it's ok to forget stuff. let it go. don't be worried on what you are missing out on in the past... focus on the positivity of the future..." So maybe an inspirational speaker isn't a career choice I should pursue.. :-D
So, everyone has memory blind spots or it's normal they don't recall certain things. Sometimes it's distorted or filled-in. Sometimes it ends up chopped so much you remember events but not their order. It's all normal, and the sooner one realises how unreliable memory can be, the better. It goes well along with my all-time favorite proverb "nobody is as smart as they believe, or as dumb as others judge." Similar thing with long-term low mood/low eneregy. Everyone's tired. But, I couldn't finish anything and for the first time I remember it was too much work to stand up after defeat. I didn't see it like that at the time, of course. So, I could reluctantly deal with not recalling a tilte of a book or not being sure who was saying what. Shortly before Christmass, however, one situation legimitely terrified me. I remember standing in front of the door, key at hand, suddenly uncertain if I'm returning or leaving. Looked down, boots were covered in fresh mud, deduced I'm coming back. Then the 'whys' and 'wheres' came back. Nothing like that has ever happened to me, and I had better continuity of events while completely wasted.It didn't take long from there to end with a psychiatrist. As to inspirational speaking, I always admired your way with words. There's bound to be loss in translation on top of communicating in text though. Not that you didn't know, I'm just acknowledging it mutually to avoid Two Generals' Problem on top of that. :D