If I promised to God that I would do/stop doing something & in exchange he would keep this one person in my life/ not let us grow apart (this person is just a friend) does He listen to those promises? Are they valid in His eyes?
God knows your heart but that’s not a promise that He will grant your request. He knows best and He loves you but it’s our will that must bent to His so I would encourage continuing your petitions, asking for discernment and fasting rather than making a “promise”.
I don’t think God wants us to be slave to some promise we made years back, so He most likely just ignores the promise and makes a decision on the petition. In other words, I don’t think making a promise will increase the chance that a prayer is answered the way we want. We have to obey the commandments, the Bible, the Catechism, and the rest of Church Tradition. As long as we are in line with these, we are free to make our own personal promises (or commitments) with ourselves (for example, do more exercise), but they won’t help in our prayers other than to maybe predispose ourselves to do better prayer.
But I tell you, do not swear an oath at all: either by heaven, for it is God’s throne;
or by the earth, for it is his footstool; or by Jerusalem, for it is the city of the Great King.
And do not swear by your head, for you cannot make even one hair white or black.
All you need to say is simply ‘Yes’ or ‘No’; anything beyond this comes from the evil one.