i agree with ShimmerWish

It's probably very stressful for your brother to make a living and support both of you without your parents and stress can make people frustrated. He may even feel resentful that they died and now he has to do it all on his own. So forgive him because it isn't easy and he's not perfect but just trying to get by. Maybe you two can sit down and talk if he ever has free time. He may want to distract himself, but it really needs to be addressed. Tell him in a calm tone how he's been making you feel and let him know you understand it's not easy for him but that he doesn't have to do it alone and that you will be able to be more understanding toward him if he's more understanding toward you. Don't complain, but just be calm as you talk so he'll be more likely to listen. As for not having anyone to talk to, there are a lot of very friendly people out there, both in person and online. You just need to look for those with similar interests and start a conversation.

You can usually get a sense of people pretty quick just being around them, so listen to your feelings around others. Also, making friends will help buffer you from bullies, but if it's physical, you should report it. Verbal is easier to deal with by staying above the fray. Don't let them bring you down but remember who you are and what makes you unique, rather than dwelling on what others say. You'll notice that, as you become less stressed, others will be less anxious around you, including bullies. Being calm calms others. Also, people really like someone with a sense of humor. Once you repair your relationship with your brother, he may also be able to help.