I frequently hit close to 25% of my grain bill as simple sugar, light brown, dark brown, plain white and going to try some Lyle's golden syrup in an upcoming brew, so I don't think that's necessarily your problem. Fermentation temps of 75 to 79 would elevate chances of fusels developing during the first few days after pitching.
If you only did two weeks in primary, then bottled for just over a week the beer is still really green, so give it more time and, in future, let it sit for three weeks in primary. You'll probably recognize the difference.
With this batch, leaving it for an extended period to condition might see the fusel flavour, alcohol bite and sort of an astringency, decrease slightly but they're not going to disappear entirely.
Chalk it up to experience/learning and make controlling of initial fermentation temps one of your next, major, priorities.