4blossoms, I've read this post and your other. I'm confused as to why you think that you're a potential love interest - it looks to me like he's just a regular study buddy. And if he IS just a regular study buddy, it's not at all weird and offensive for him to take days to respond to your email. It's likely he was too busy with friends and other stuff to think about tutoring over the weekend.
Has he shown any interest in dating you? Is there any romance which you've neglected to tell us?
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.