I'm really sorry to hear that. I can't imagine losing a sibling so young. I end up doing the same thing when I get overwhelmed or if I feel like I'm being ignored or rejected.
I'm still learning those things myself honestly. I think you're deserving of love, because everyone deserves love. There are so many qualities about you that make you, you. And I think you deserve to feel love, happiness, and closeness with other people. Trusting others is hard because it's letting yourself be vulnerable and open to another person, that's scary. I guess what helps me is that when I allow myself to be open with others, I tell myself "Okay. I'm going to share my heart with someone. If they don't like it or don't appreciate it, that doesn't mean that I'm not worthy of being loved. That just means that person isn't right for me. I trust that most people are good and have good intentions, most of us want to be accepted and loved. I know that even if this isn't the right person, there's someone out there who is. And I deserve to have people in my life who I can trust and who trust me."
Sorry for the long rant. I hope some of this helps a little. :)