suspicious infusion

Made vodka/jolly rancher infusions and they sat in a dark cabinet for about 2.5 months. Came back for a quick taste and the vodka was searing. Felt it burn my stomach for a solid 15 minutes after taking a slow shot for tasting. I’m not new to drinking, so I can say that it was about twice (or maybe a bit more) as strong as it was when I made it. By strong, I mean the burn that comes along with it. Made me tipsy immediately even on a full stomach. Anybody with experience in infusions know what might have happened? I’m not sure if the sugar over time raised the alcohol content or if I’m just hallucinating.