Struggle with vulnerability.
Idk why but whenever I cry in front of someone, I really regret it later. Saying how I feel or crying or getting frustrated...afterwards I always think I should've just kept it together and played it cool. But nope, instead I cried or shouted or stormed off.
And in my defence, many people do sometimes use what you tell them in confidence against you when you have an argument with them later.
Eventually you just stop trusting people and start thinking, "Why even share?" If being honest or vulnerable can be used against you later on, then it almost safer to just keep everything to myself, even if that's not what I actually want.