Mt, I have had almost the exact same pattern at 6 months. No leakage while lying down or sitting, but as soon as I stood up I'd start to leak, and if I started walking I'd lose all control. This was despite doing Kegels regularly. The muscles simply were not strong enough to keep the urethra closed when there was any stress at all.
For me, it's taken nearly a year to get to the point where I can walk without leaking.
I remember that at six months I was seriously thinking about a sling or other surgical intervention, but now I'm glad I waited. Give it another 6-12 months, keep doing the kegels, and you will almost certainly see improvement. Hang in there!
Jeff