Losing again and again

If you cant trust your mate/significant other with your most inner fears and thoughts without fear of being laughed at or told you are being silly, then who can you tell? I think i know the answer, a stranger! Or even someone you dont know all that well. Sometimes all you need is someone to listen, or say" yeah, it may be a silly thought but hey, you are doing the best job you can, alone" or " i may not agree with you, but as your bf, im on your side,whatever you need, im here". Since when did those words become soooo difficult to find and say to your loved one. Maybe i dont necessarily even want your opinion, b/c i dont need it, its irrelevant , but being ignorant is beyond me. 
I guess thats why ive become one of those people that keep my private stuff private, lol besides here! I dont post on facebook, tell gossip, open my heart like i used to b/c ive learned it will very easily get stepped on, used against you etc. I guess i learned my lesson again, the hard way. Keep all my worries, my fears, my highs and my lows to myself, bc they arent appreciated, they are either ignored or made fun of. 
Thats fine, i can do that, but it  poses the question again , how can you have any type of long lasting or meaningful relationship if you keep losing trust over and over, only in a different way each time. Promises mean nothing without action. 
xoxox