One day at a time. Every time you want a cigarette but don’t give in, you have built strength. Use that strength to better resist the next urge. Really internalize that what you are doing is strong and powerful. Each victory accumulates and supports those to come.
Get active. The absolute worst thing you can do is “nothing”. You will feel so much better getting out there and doing good work with your neighbors. Looking for local mutual aid orgs in your area is a good start. If you can’t find any, start one yourself! Another commenter here goes into greater detail, but you can start very small! Or arrange some meetups around skill-sharing. You probably have a useful skill or knowledge that others could benefit from, and I’m sure there’s things you’d like to learn as well. Doing things like this builds community bonds, and strengthens us all. Don’t wallow, get involved!