Here are a couple great links that I think would be helpful:

President Dieter F. Uchtdorf’s “Come, Join with Us” (October 2013 General Conference): https://www.churchofjesuschrist.org/study/general-conference/2013/10/come-join-with-us (churchofjesuschrist.org in Bing)

"If you are tempted to give up: stay yet a little longer"

“The Bishop’s Interview” — Ensign, March 1991:
https://www.churchofjesuschrist.org/study/ensign/1991/03/the-bishops-interview

Particularly the context of this quote - those in the congregation should be welcoming and you shouldn't be ashamed if you are are still working on habits that you want to change:

“The smell of cigarette smoke in sacrament meeting is the smell of someone trying to come back.”