Hi Vickki, Welcome to ATP.
I'm not sure what the question is so if I miss by a mile, let me know. You have had a Lobelia aguana growing in a 12 inch or so pot for the last year. You keep moving it, trying to find the perfect place? Because it's not blooming? Because it is not healthy? Because....?
Why are you moving it back and forth between the shade and sunny spot?
These plants will handle full sun but will live in part shade. It may be that it's not blooming because it should be planted in the ground - this is a huge plant often getting 5 feet in every direction.
If you must keep it in a pot, you need a bigger pot. I would find something insulated (a lot of plants hate hot roots) and large, maybe 10 or 15 gallons.
Daisy