A little background on me first ...

I have never been able to breathe through my nose. It always took deliberate effort, and I would lapse back to mouth breathing unconsciously.

So now that I've discovered mewing, I'm interested to see if it will be able to fix my breathing issues. However, my main problem is that there seems to be very little space in my mouth. If i were to lay out my tongue straight, it would extend beyond my teeth by about 1cm.

It seems to be impossible to "start" from the back of my tongue and push it up against the roof of my mouth AND place the tip of my tongue at my incisive papilla. Either there isn't enough room, or my tongue isn't "flexible" enough right now. So currently I'm focusing on jaw exercises, and consciously placing my tongue at my incisive papilla, hoping this will push my face "forwards" and eventually give me more room to place my entire tongue on the roof of my mouth. Right now, I'm able to able to breath through my nose using conscious effort.

My main concern is that am I doing this right?

PS: I've have completed invisalign (basically fancy braces) done to fix my crooked teeth, if it matters.