Selfish

My bf always says I'm selfish. I don't think I am. I know I could be more thoughtful but I don't see how I'm selfish. 
​He says I don't care about anyone's feelings but my own. Just thee day he had a bad day at work and he said I showed that I didn't care but I didbt aknowkedge it. I need some advice on how to get better with this.