hey don't beat yourself up over it. i do agree, you could have bitten off more than you could chew. but assuming you are to continue with this...
can you post the high poly? it will be helpful for crits as its hard to go by at the moment. but its certainly lacking a lot of detail thats in the concept, i assume this is because you are new to high poly modelling and are struggling.
it seems you used a floater to indent that circular shape on the front, which could have easily been integrated into the model, so now you will be left with a lot of cleanup. also make sure you really taper in indentations, so when they bake down they are more apparent.
for the low poly, the topology looks a bit iffy, always focus purely on the silhouette, as everything else can be baked down. you have a lot of unnecessary edge loops.
keep at it, or have a break and revisit it