Is this a red flag or am I overthinking?

My boyfriend and I are in our mid 20s and have been together for just over 7 months now. When we first got together, he explained to me that he wasn’t an overly emotional person and doesn’t open up much. He also said all of his previous girlfriends nagged him about burying his feelings. Despite this, we do have a great relationship but we don’t talk much in depth about our future as much as I’d like to. Now that I am older, in this relationship my overall goal is to spend my life with him and have a future together, marriage, kids, etc. He’s never expressed much of that to me so I started to think a lot about it and decided to ask him about it last night. He avoided the question at first, telling me I had nothing to worry about and that he wasn’t going to leave me and wanted to be with me, but never addressing the whole “having a future together” part. I went back to the question again, asking if he could truly see a future with us together as it was something that’s important to me. Again he just told me to stop overthinking, and that he wasn’t just “with me to be with me” and that he lives his life “day by day”. I wasn’t overly happy with his response but didn’t push it on him anymore. As great as he is, I don’t want to keep putting effort into this relationship if we don’t have the same goals in life. I don’t know if that was his response because he doesn’t open up well or just because he truly doesn’t have the same aspirations as I do. Am I overthinking things or does it seem like he isn’t willing to commit the same way I am? I need some help before I go crazy from overthinking 😓😓