yea the container has drainage holes i made sure also the soil is well ventilated now and ill try to water it less. should i put it in the fridge so that it goes into dormancy ?

No need to put it fridge right away. Nov or even Dec should be OK. You will know when it has dropped its leaves. Do you have cool location like an unheated garage/shed?

yea i have a garage but in the winter its -20 dergrees outside is that ok ?

But the garage may be a lot warmer. I have a shed that has not much of insulation and no heating. And it rarely goes below 20F in my zone. Outside may drop to 0F or below. I also pile up stuff around my plants for more protection. But I would suggest a spot where it does not go below freezing for such a young and probably a bit stressed plant.

I have a similar sized plant that grew from seed from the mother plant that is in the ground. I plan to leave the plant in the pot dug in the ground under another bush for added protection. Add mulch around it and lots of leaves too.

When you say -20 is it F or C?

In general, your plant will do better outside. Crape myrtles are zone 7 plants. I am in zone 6b. In ground they can take that kind of temperatures. In pot you need to be careful. Ideally, keep it just above freezing say for 2 months or so.

-20 C...o got you... thanks