Haven't Won Single Game Since Purchase Of 10 Win EXP Boost

On my other account I'm leveling, the instant I purchased a "per win" EXP Boost I often started getting matched against Ranked players, including anywhere from Silver to Platinum, in my pre-level 30 queues.. I've also lost 7 or 8 games in a row, and haven't won a single game since purchasing it.. despite previously having a pretty decent win rate (somewhere 70%+). This is pretty ridiculous and I can't even fathom why this is happening. I've been trying my best to relax and carry but it's simply stressful and impossible when matched with other players who are new and don't know how to handle a real mid / high tier players. Not even to mention how frustrating it is to see the enemy has full rune pages, runes, and masteries while I'm over here pre-level 30 with tier 2 runes.

If this is really the result of buying this boost, I'll never buy another one again. The stress of facing people who aren't leveling when I'm just trying to relax, level up, and have a good time, is way too much.