Why is he suddenly distant? (He admitted to)?

My boyfriend has been acting distant and I am not sure why and what I should do about it. He has a lot of responsibilities with work and school and he is often busy and I haven’t seen him in a week and I won’t see him until maybe next week. I told him that because our relationship is still quite early and new maybe it would be best for us to be friends because it seemed like he may need to take more time for himself and work, but he insisted that he wanted to be with me. He then said that “I know that I am quite distant sorry about that”. I wanted to ask him why but I didn’t want to overwhelm him.. but I really want to know why he is distant. Where he doesn’t really initiate solid contact or connection with me. When we’re together in person everything is fine, but when he’s away it’s like he’s quite short in answers and doesn’t really reach out. Another factor is that this is my first relationship and this is his first relationship prior to his previous relationship with his ex that last almost 3 years and ended in January. Because this is my first relationship I was very unsure about the relationship and I kept changing my mind if I wanted to be with him. This time I am sure even though it did take time for to be sure. Help anyone?
Why is he suddenly distant? (He admitted to)?
Post Opinion