Paul uses "yoke of slavery" in the following passage to refer to trying to be right with God by keeping his commands, and Paul uses "circumcision" as an example of one of the commands. One thing he mentions elsewhere, but not here, is that it is impossible to "obey the whole law" to be right with God.
It is for freedom that Christ has set us free. Stand firm, then, and do not let yourselves be burdened again by a yoke of slavery. Mark my words! I, Paul, tell you that if you let yourselves be circumcised, Christ will be of no value to you at all. Again I declare to every man who lets himself be circumcised that he is obligated to obey the whole law. You who are trying to be justified by law have been alienated from Christ; you have fallen away from grace. (Galatians 5:1-4, 1984 NIV)
We are right with God because of Jesus' death. If you believe in Jesus (and you clearly seem to be trying to live to please him), everything you do that might be a sin is already forgiven (i.e., you are saved). Jesus didn't die so we could put God's Old Testament Law behind us and come under the commands in the New Testament. We are freed from having to keep any commands or rules to be right with God.
But now, by dying to what once bound us, we have been released from the law so that we serve in the new way of the Spirit, and not in the old way of the written code. (Romans 7:6, 1984 NIV) (Also see Romans chapter 8.)
However, Jesus is still Lord and God, and still loves you
So we make it our goal to please him ... (2 Corinthians 5:9a, 1984 NIV) Just don't "live according to the sinful nature" (from Romans 8:5), which is not too hard (Matthew 11:28-30) if you make this a habit:
Rather, clothe yourselves with the Lord Jesus Christ, and do not think about how to gratify the desires of the sinful nature. (Romans 13:14, 1984 NIV)
College is a time when some people's faith is tested severely. Try to hang out with friends who are also trying to live pleasingly to Jesus, and the above will be easier, and remember God loves you and accepts you even if you sin.