Why am I playing against Plat players every game as high silver/low gold

I've finally made it to Gold V and I play with my boyfriend who is Silver 2 so why is it that every game we play, we are matched against plat players. We have played games where every person on our team is in silver except me in gold 5 and the entire enemy team was in plat except 1 person in high silver, and this is pretty consistent for most of our games. Its very frustrating to constantly get matched against a team that is much better than mine.