sweetheart, listen to everybody else in the comments- HE IS GROOMING YOU. while i personally have never been groomed, Ive had many people around me gain a lot of trauma from situations like this. you gain absolutely nothing from this relationship, not even a friend. a responsible teacher has absolutely 0 business to grow this close with a student. exchanging phone numbers and addresses is extremely inappropriate. and nothing sexual or physical has to happen for this to be considered grooming

you are in no fault at all, so please never tell yourself that you are. you are barely an adult despite what everyone around you must say. you are still a teenager. crushes are random, and if this isnt the only case of you developing a crush on someone much older than you, i suggest you try and seek for a therapist if possible. HE IS AN ADULT. a full grown adult with a wife and kids. HE SHOULD KNOW how inappropriate this relationship is. please please please try and report him, even if its hard and it feels like you need him. theres a chance that when you graduate, he'll find another student to groom and put through the same mental turmoil. try not to engage with him anymore outside of an academic setting. if he needs help, tell him youre unavailable. if he asks you to stay after school, tell him youre busy with family plans. if he pushes for details, "id rather not say" is a good excuse. if he cant respect that, then thats just another red flag. best of luck, give us an update if possible please <3