stand in (someone's or something's) way
1. To obstruct or act as an impasse to someone or something. I'm dying to get up close to the band, but this crowd of people is standing in my way. They built massive banks to stand in the river's way should it ever flood like that again.
2. To hamper, impede, or prevent someone's or something's action or progress. Several senators are standing in the bill's way, ensuring that it will not pass. The only thing standing in your way is your own attitude. You could accomplish so much if you had a more positive mindset!