It's very common for an engine to run at a higher idle in the air, after warmup, than
on the ground after you've just fired it up. Learn to play with the idle trim for best results.
(Or get a computer radio which has "idle down", which takes care of this specific problem)
The prop is able to "unload" in the air, and you're probably picking up an extra
hundred or so rpm, even at the idle setting, in the air. This will be sufficient to keep it flying.
(The prop "unloads" by propelling the plane, which presents less resistance in air than grounded)

Also, don't expect that a carb setting should last a year. (even if it does, sometimes)
Given different weather, different batch of fuel, etc... it's not uncommon to retune often.
(I do this before every "first flight" of the day, and sometimes in between, to tweak)
Optimal settings may vary from day to day, or from morning to afternoon, by a few clicks.

Finally... the 10X7 isn't doing much to help slow you down.
On that engine, I'd suggest trying an 11x5. You'll trade off some top end speed,
for a greater static thrust, and a better "braking" effect on downlines and landings.

At the very least, try the 11x6 as you mentioned.
That's still quite a load for a .46, but it will give you better braking than the 10x7.