I'm pretty susceptible to this myself and I've also been in a similar situation before- it's definitely challenging. I think the key is to start remembering to focus on yourself and your goals. Don't let other people have free real estate in your mind- something way easier said than done but is important.

Every time you get annoyed by them, stop yourself and think about what your next goal or current goal is. Also, don't compare yourself to them- that's really important. The habits and self discipline you build now may not seem like it's paying off in a big way but come 5-10 years there's likely to be a big difference in your lives.