Toxic compounds, weirder situation then usual, much weirder

Ok so I'm making some hard alcohol from a sugar-wash. I used too little yeast and fermentation ended up halting at like 7% ABV, it then stood around for like a week and a half till I got the new yeast. I freeze distilled most of it after it finished, hopefully at around 13% but can't tell because I added some water with the new yeast, used a sterile syringe and distilled water. Because I used a new container and my calculations were waaaay off, I got something really sweet, so I'm using it as a base for alcoholic lemonade instead of the usual ultrasonic aged whisky I make. I drank like 2 glasses and I'm fine, but I drank them slowly in the evenings. It has a bit of a weird off-taste, but, to me at least, not bad, more fermenty, even though stronger then the one I get when I make kwass(didn't get time to turbo clean it yet though). My question is, is there any chance it has something harmful in it from just a sugar wash? Because with the halt and all the process took like a month, even though it was mostly hermetically sealed for that time. I'm a bit paranoid about getting drunk on it. Even after freeze distilling it's not strong enough to light on fire but if I heat like 100 ml of it and keep an open flame on top, I get like a second of yellow flame(methanol probably) then it goes out and start burning transparent or blue in the dark, I never let it go till the end cause it seems like it wanted to burn for a while. By the burn test the methanol content should not be an issue(I think). Any thoughts?