I may be misunderstanding what you are saying, but are you suggesting that following God's Law means you are rejecting the Holy Spirit? That is a very dangerous thing to say and should concern you if that's what you mean.
Romans 14:5 is CLEARLY about food if you read the context, not the Law or Feast Days. Please read starting at verse 1 to get the context and count how many times food or eating is mentioned. People were arguing about when to fast, this was a big debate back in the day. He is just saying it doesn't matter what day, it's between you and God.
Colossians 2:16-17 also says the opposite of what you think. Do you really think that the Pagans would give them a hard time for NOT keeping the Feast Days???? Also, the Greek word for "regarding" literally means "portion".
μέρος méros, mer'-os; from an obsolete but more primary form of μείρομαι meíromai (to get as a section or allotment); a division or share (literally or figuratively, in a wide application):—behalf, course, coast, craft, particular (+ -ly), part (+ -ly), piece, portion, respect, side, some sort(-what).
I encourage you to do a word study on this Greek word and see how often it is translated as it is here, I think the answer will surprise you.
So what this verse really says in the Greek is don't let anyone judge you in food or drink or WHILE TAKING PART of a Feast day ..... Taking a PORTION of the Feast is what it's saying.
The commandments Jesus gave came from Torah, please show me one that didn't or show me one that breaks Torah.
Do you think that Jesus is someone different than the one who gave Moses the Law?
Do you think those commandments were not His commandments?
Also, in case you didn't know, the "Law of Moses" which you seem to have disdain by the way you referred to it came from God, not Moses. Also, you said Jesus's words are truth and I agree. But did you know that the Bible also says that the Torah (Law) is truth?
Jesus himself said that people who break the Law or teach others to do so will be LEAST in the kingdom of God.
I hope you think about what I'm saying and verify these things for yourself. Please feel free to reach out to me if you have questions or what to show me where I'm wrong.