First three are fine. Just be aware "gotten" is an American English word. For the fourth and fifth sentences, I would replace "'might" with "may". The fourth sentence should read "It may be a very long time before I get back here" but it sounds a bit long and unwieldly! I would just replace both sentences with "It may be a long time before I return."

I am not use to the marriage or i am still adjusting to marriage life. I am not use to my new job or I am still adjusting to my new job. I am not use to my new teeth or i am still adjusting to my new teeth. It may be a long while before i get back (if you use here you must name where?) It may be a long time before i return.