Help!!!!! I'm so selfish and I hate it

What are ways I can practice being selfless ? Not everything I do is selfish , for example , if someone needs a ride and I don't feel like giving them one or they don't have gas money , I'll still do it . I'll open my house to friends and family that need somewhere to live ... sometimes I even stress myself out trying to help others but when it comes to certain things, I am a class A bitch about others using my things. I HATE when people wear my clothes , especially when my husband wears my socks. I HATE sharing my food , space , hair products or just about anything. Last week my husband sister wore my scarf for like three days straight and it drove me nuts. I tried so hard not to say anything but it bothered me so much. Today I let his cousin use my Netflix account but when I left , I told them to log out ... when we came back I thought they were still logged in and it pissed me off so bad!!! I took my hair products out the bathroom bc I hate when people use them , even my husband . I hate I'm like this. I'm disgusted with myself honestly . How do I stop this nonsense???