My loafers might be too big? ( Paraboot reims) looking for size 8

[admiral sug]

I think my loafer might be to big. I bought paraboot Reims loafer and the fit is very comfortable with a little space in the toe area. When I stick my finger in the heal it does pinch slightly if I squish my toes up my index finger will easily go in. The problem is when I walk my heel slides out completely with Nike socks. I'm pretty sure if I went half size down I will have no wiggle room in toe area. I've only had the shoe for a couple of days and the sole is very thick and has not breaken in at all. These are my second pair of loafers and my Cole haan penny's did Not do this. I am starting to think its the shape of my foot because my feet is very skinny. Will this get worse? The shoes are very ill fitting.