Hi, I'd like to help you with your question.
If your partner does not want to discuss your relationship, you are going to have a hard time trying to get information about his feelings out of him.
You can try asking him again, if you feel it would help. This time, tell him that it is important to you to know how he feels.
Most likely, though, it is probably because he does not feel comfortable sharing his feelings yet. Most men are not. They feel that being with someone is enough and they don't need to say how they feel. Just because he does not say he loves you does not mean he doesn't. He may just not want to say it or not feel it is the right time yet.
How do you feel about how he treats you? Is he nice to you, thoughtful and kind? This will tell you a lot about how he feels. Also, if he respects you then you know you are important to him.
He may also just want to be sure he is in love before he says it. It may be that he feels once he says it, he is in a committed and important relationship. Some guys do take a long time until they feel comfortable. And 4 months is not a long time. I would give your relationship at least a year, providing that it is going well, before you consider moving on.
I hope this has helped you,