My boyfriend has commitment issues
You seek happiness, you have the same ambitions, he loves you, that's obvious, except that the words "will you marry me" will not come out of his mouth... Doubts, selfishness, fear of commitment? How to make him change his mind? How to overcome fear of commitment, a scourge that affects more and more men?
He says he's not ready, can't afford to take risks, that he's too young, doesn't feel ready for a serious relationship... what if he's been through a bad experience? You must understand the source of his discomfort. The causes may be much more complex than they look. Commitment involves taking a long term decisions, the anguish of doubt can therefore be a real burden for him. What if he took the wrong decision?
Certainly no ultimatum
Once you identify the causes of his reluctance to engagement, there's no need to pressure him, try to reassure him and show him that engagement does not necessarily rhyme with imprisonment. The first attitude to adopt is not to trigger or fuel this fear of commitment. If he's not ready for marriage but is flexible for the future, start with a less restrictive subject, talk about engagement, and tell him that marriage can wait... Take the time to understand what's blocking him and do not invade him.
Don't let the subject obsess you
By dint of thinking about marriage, you tend to forget your relationship and more importantly, you start to question yourself, trying to figure out what you did wrong... Don't concentrate your life on marriage! Get out, enjoy your favorite activities, and remember to savor life with or without him, be independent... Make him understand that you're capable of taking care of yourself without him.