Here's what I believe to be true:
Those that worry about their salvation are saved.
Those that don't care about their salvation, don't worry about it. Like atheists, for instance. They don't go around worrying about whether or not they're saved.
Only SAVED persons worry they may not really be saved.
John 3:16
As for liking to do righteousness:
I've found (I'm a lot older than you) that as you walk with God, you learn more and more.
The change in us could be immediate, or it may take some time.
Some small changes will most probably happen immediately, but some will take longer.
For instance,,, I didn't understand about forgiveness till just about 10 years ago, and I've been Christian a really long time, and studying too. We could get into this more if you want to.
We just can't know everything all at once, but God is patient and loving with us.
2 Peter 3:9
As to the other cheek:
What your pastor was saying, is NOT what Jesus was saying. I could also get into this.
Jesus never said to stand around and take it. He said to be gentle as doves and wise as serpents.
He got mad at things just like we do...a righteous mad. Nothing wrong with that. When we see sin we SHOULD be mad...if someone attacks us, it's like the enemy attacking us....we SHOULD be upset. The devil scours the earth, seeking whom he will devour. We should stand up to him.
Loving our enemies.
What is love anyway?
Is it just a feeling? No.
It's not doing harm to them.
It's helping them if necessary.
It's praying for their soul.
If they give us too much grief,,,it's even OK to keep them out of our life...
however, we are not to hate them or to seek vengeance.
And love is not that lovey dovey feeling we have for a loved one...
Love means doing the right thing.
Try not to cuss them out in your mind.... remember Jesus looks at the heart.
This takes patience and maybe time....but one day you WILL achieve this.
Jesus will always forgive you your shortcomings.
1 John 1:8-10
1 John 2:1
As to Mathew 23....
Are you making believe to be a Christian or do you really desire to be one?
This is what Matthew was talking about re Jesus.
The Pharisees were following the law to a T,,,,but inside they were rotten and did not love God.
The very fact that you're worried about this shows your love for God.
Philippians 4:8-9
8Finally, brethren, whatever is true, whatever is honorable, whatever is right, whatever is pure, whatever is lovely, whatever is of good repute, if there is any excellence and if anything worthy of praise, dwell on these things.
9The things you have learned and received and heard and seen in me, practice these things, and the God of peace will be with you.