In Galatians 5:1, Paul declared that Christ had set us free and no longer bound by the Law of Moses. This applies to both Jews and Gentiles. Circumcision as a practice of the Jews, no longer be a prerequisite to receive the Grace given by Jesus Christ. So it doesn't matter for the Jews to practise circumcision as their tradition, and it does no harm to Gentiles not to practise circumcision.
Paul did not against circumcision on Jews, but against circumcision on the Gentiles. As he said in Galatians 5:3-4
3 Again I declare to every man who lets himself be circumcised that he is obligated to obey the whole law.
4 You who are trying to be justified by the law have been alienated from Christ; you have fallen away from grace.
Now the argument is, if circumcision no longer a prerequisite, why would Paul reacted so strongly against Gentiles took the circumcision? The answer is straight forward but hidden. At that time, Gentiles had no knowledge of circumcision. It was introduced by the Jews false teachers, with an intention to turn the Gentiles to Jews, so as to under their influence. So Paul warned the Gentiles, if they accepted circumcision, they were bound by the Law of Moses, which was impossible to comply the whole Law, and no longer be free.
Then why would Paul allowed Timothy to get circumcision?
It should be noted that Paul had two workers with him, Timothy and Titus. Timothy mother was a Jew, Titus was Gentile. Paul was preaching in Synagogues where Gentiles were forbidden to go in. So Paul circumcised Timothy, not because of the Law of Moses, but prepared Timothy to have no obstruction to preach the Gospel to the Jews. However, Paul was strongly against Titus to be circumcised, while they were in Jerusalem (Galatians 2:3), facing the false believers as Paul described (Galatians 2:4).
The circumcision of Abraham was the sign of the covenant between the Lord and Abraham and his descendants (Genesis 9-11). It was a covenant specific to Abraham and his descendants, not to the Gentiles. The Jews had no right to extend the covenant of the Lord to the Gentiles as it is a sovereignty of the Lord.
Is Torah a curse? Absolutely not. Today the Jews are still free to accept circumcision as a sign they are descendants of Abraham. Gentiles remain uncircumcised to follow Jesus. Both of us are together the sons of the Lord, through the salvation of the Christ to become one.