<human>: My boyfriend and I usually don't have an issue with sharing our feelings and communicating with each other, but something happened in his life recently that he vented about to one of his female friends instead of me. He admits to me that he's not open with his feelings to people, and that I'm someone who has "cracked his shell". 

I'm in my first year of college and he's still in high school. Two nights ago, he told me he was officially dropping out of high school. When I asked why, he told me "cuz it would be fun", which was such a bullshit response to hear. I told him I'm always here for him and that I've accepted him throughout our relationship (he has a lot of stuff from his past he's told me about). He ended up going to bed and not telling me what's really going on, but he said he told his female friend he met online 5 years ago everything. He said he feels ashamed and that's why he's not telling me.

It might be worth mentioning we've been fighting quite a bit over the past few days and both of us have overreacted to things the other has said, but we haven't argued about anything in the past 48 hours or so.

I understand his feeling of shame for not wanting to tell me, but it still hurts knowing that he felt like he could confide in someone else instead of me first. I'm not sure how I can express these feelings or if I even should, or how to go about with this situation. I feel like he doesn't think he can talk to me about things anymore because of our fighting.

Could you distill the essence of the text into 1-3 sentences?
<bot>: boyfriend confided in his female friend about his reasons for dropping out of high school instead of me, he refuses to tell me because he feels ashamed but I'm also hurt he decided to confide in his friend instead of me first.