What is the ruling on abandoning matters that I promised to abandon in exchange for the cessation of what troubles me, knowing that some of them are impermissible to abandon and others are permissible?

A vow (nadhr) is a commitment by a legally responsible Muslim to perform an act of worship for Allah. It can be made verbally, in writing, or by gesture. There is no specific formula for it; rather, any statement that conveys a sense of commitment suffices. The formula mentioned in the question is not considered a vow because it does not convey a sense of commitment. A conditional vow is disliked by the majority of jurists, and some of them disliked vows absolutely because they do not bring about good; rather, they are used to extract from the miserly. This prohibition signifies disliking (karahah), not outright prohibition (tahrim). It is recommended for a Muslim to adhere to what he has resolved to do, and if he verbalizes it, it is even more imperative to comply, unless what he resolved to do is disliked, forbidden, or involves abandoning a recommended or obligatory act.