There's plenty of people we don't like; perhaps even hate. It's human nature and completely rational. Please do remember that how you feel is very real, never pass it off as something small. If you feel a certain way, know that it is real. Even if it seems irrational or stupid, you are human and how you feel is a delicate subject so treat others and yourself kindly and take consideration to every emotion. Here's how to deal with hate: 1. If you feel it's necessary, communicate with that person in a mature manner. No need for drama, but attempt to talk it out with this person. Maybe there is a miscommunication and a little explanation from both sides needs to be spoken. As I said though, remember that the other persons feelings matter as much as yours; find a medium for the situation. 2. Ignore it. If it truly is something small like they ate your food without asking, perhaps casually bring it up saying "hey could you please ask next time" and the situation is solved. Or simply let it go. If it could turn into a fight, ignore it unless things escalate extremely (such as stealing food from you to take to their home because they're lazy, not because they don't have money). 3. Keep distance for a while. Sometimes all you need is some space from people who drive you crazy. 4. Lastly, if the situation is dire, never contact them again. Some situations are best left untouched and if someone hurts you that bad, it's not wrong to leave them. Your mental health is more important than a detrimental friendship. You are delicate and don't deserve to be treated poorly. Cherish yourself. Love yourself. The less hate in your life, the better it'll be. It takes practice and patience, and I hope one day you can all find a peace with yourself and your chosen circle of companions. Never let someone poisonous kill you.
How to manage disliking someone
I totally agree @stargaze it's like you don't want to disrupt the order of things and be the "bad guy," even though you aren't really doing anything wrong! It can be really hard to navigate, even when its not as severe as disliking someone. Sometimes it's actually harder when you like someone and you have to solve things in a way that they'll still like you, lol!!
I have a bad experience with point #2. I used to share a living in a shared apartment during college. One of my apartment-mate ALWAYS use my utensils and cooking tools without asking. It's hard to confront her because I didn't want to make a big deal (that's my fault). She even stole my tofu and used my skincare products without asking. I don't sharing if she asks but I dislike it when she clearly uses it without even trying to put it back...I'm so glad I'm done with college.