Opening up like that to someone is something you do for you. It's really not done for anyone else's benefit but you own. It's means to put your thoughts & feelings out there and get them off your chest. It's not healthy to constantly keep them locked inside.

There comes a time in life when you find that you need to stop worrying so much about what others may think and that you need to stand in your truth - which includes expressing what you are thinking and how you are feeling. It's only challenging and difficult at first - but it gets easier over time and with more practice. : )

Please don't allow his reaction to turn you off from doing this again in the future. His reaction is a product of his own mindset and state of consciousness and NOT a reflection of what others will think and how others will react - as they are unique and individualistic in their own right. As someone else appropriately noted - if you had shared with us what you shared with your boyfriend, our reactions would have been quite different. Look at his as the 'exception' and not the 'rule'.

It's good that you did this whether you recognize that or not right now. It's good for you in the long run - it's an important learning experience (NOT in the sense of having done anything wrong or making a mistake), but something that was necessary and something you grow from having gone through. It's only a headache for you in the short-term. Good job for having the courage and conviction to do this. It will be easier the next time you need to do this because now you have experience under your belt. : )