I have quarreled with someone who envied me and interfered in my affairs. Am I sinful for that?

The Prophet, peace and blessings be upon him, forbade turning away from each other and boycotting Muslims for more than three nights, unless the boycott is a means to repel harm in religious or worldly matters, as Ibn Abd al-Barr mentioned. It is forbidden to accuse a Muslim of envy without proof, and the basic principle is to think good of Muslims and interpret their words in the best possible light, based on the words of Allah the Almighty: ﴿O YOU WHO HAVE BELIEVED, AVOID MUCH [NEGATIVE] ASSUMPTION. INDEED SOME ASSUMPTION IS SINFUL.﴾, and based on the words of Umar ibn al-Khattab: "Never think ill of a word uttered by a Muslim, when you can find a good interpretation for it."