Wolfox

I see. I can understand why it's hard, there's 1, maybe 2 people on Earth I would trust with absolutely any of my issues...? so yeah, opening up is difficult. I suppose it's a matter of right person, right time, right circumstances.

oh right! I forgot to mention trust issues due to getting stabbed in the back by "friends"

Hate to create excuses but yeah...

I only have 2 good friends that remained after that stabbing by "friends" took place. It is natural to have only 1-2 actual friends. It's human society, most are actually not worthy of your time. Just gotta learn to be prepared for it, never trust completely, always protect yourself. 

Also, nobody wants to rub his/her happiness in your face, regardless of how it feels to you. When you are happy, it's obvious to everyone. That's the case with your sister and her BF. They don't even remotely think "oh, let's rub our happiness in Wolfox's unhappy face, it will be fun!". They are just enjoying their lives together and, frankly, there is nothing for them to be ashamed of about this.

Finally, I bet that everyone has bad times and troubles, just like yours. You're just too focused on their good times, that completely ignore the hardships they went through. They did go through them though, and you have to do the same with your hardships. Our problems are ours and ours alone, and we must take action to defeat them. That like rule #1 in life. Nobody will solve your problems for you.