If you look at what God chides people for in OT prophecy, it's much more harmful things than smoking and selfishness. It's cheating widows out of their inheritance, leading people into religious deception and oppression... trickery, trampling, and brutality in the name of God.
The collective advice above should help.
I encourage you to think about salvation by grace, not by our own perfection. We can never be completely righteous in God's sight, without His help -- which He provided through a one-time redemptive act (it's Easter season -- celebrate it!).
I was fortunate to come to Christianity at a time when uniqueness, simple living, and asceticism was looked up to -- it was a fun challenge to live sacrificially, so we erred in the other direction (pride, demanding more of ourselves than God expected). People thought they could live like Ghandi.
Also how does one walk in the Spirit? Do I need to make a list of things I can and can not do?
Heh, isn't that irony?
Jesus promised to send the Holy Spirit to be with us when He left. He was a guide, friend, adviser, teacher-rabbi when He walked the earth. He walked beside people, and reasoned to challenge our ethics and intents.
God's Holy Spirit stays with us in a similar way -- challenging, nudging, giving insight, guiding. He is our help.
If we strive so hard to impress God that we push aside this help, then we're not really connecting with God -- we're trying to prove ourselves God-worthy. Relax a little. Sit and listen. Follow the hints or test them to see which are worth listening to. Listen to the convictions too, but not the bruising condemnations within yourself. The Spirit is life.
There is a trick that parents and teachers do to keep a child from doing something bad: they distract them. If kids are fighting over one toy, they bring over two toys and suddenly there's something new to look at. Find some devices that you know will be worthwhile distractions for yourself. A glass of juice. A walk outside. A song. Make it easier on yourself by breaking up old brain patterns.