Matchmaking against silver/gold/plat as someone under lvl 30

I'm a new player with a level 26 account. I don't even have all the rune.mastery slots and all my runes are tier 2 runes. I almost always play solo instead of queueing with someone else.

Yet somehow, I keep on finding that the enemy team is full of people in silver. Some times there's even a gold or plat person my team or the enemy team. In some games I'm the only one that's under level 30. I only won about 6 games in my last 20 games.

I think maybe it's because the starting mmr for people going into draft pick is silver. It feels so unfair since I feel I have on influence on the game. I feel like my skill level is so far below everyone else in the game. In some games my team gets stomped and some games 1 or 2 people on my team totally stomps the enemy team.

Any other new players experienced this?