Question
Someone once told me he made a neder every week that he would not eat sweets in that week so that he could stave off any weight gain. Using that logic, can I, in order to not get angry which I am trying to work on, make a neder that I will never become angry
Answer
I strongly recommend against it. Although one can make oaths and vows on a wide range of items. The severity of the transgression if not kept is quite significant. There is precedent in Shas for using oaths and vows to aid one in his spiritual growth, but as stated earlier I very very strongly recommend finding another incentive. I admire your desire and determination to perfecting your midos, that is something we should all learn from. Thank you.