Hi there! You definitely sound like me. For years I've had the same struggles. Make plans and get super excited for them only to not be able to follow through. For a few years I was always told it was because of depression but no meds were working until I found a new doctor who suggested ADD. I got put on Strattera and things started looking better but I was still having the same really low lows and really high highs, everything was black and white, no grey area. So my doctor added Wellbutrin to the mix. It's definitely helped balance things out better but I'm still having some trouble with those lows and highs. I'm hopeful though an appointment with my doctor to see about upping the Wellbutrin dosage will be a positive one.
But I think you'll definitely be glad you're finally seeing the doctor and being proactive about it. I know medication works differently for everybody but trust the doctor, give it time, and I'm sure you'll find what works best for you and soon you'll find yourself checking off your accomplished goals.