Appearance affects most people, whether they want to admit it or not. :/ I'm horribly embarrassed about the dark circles around my eyes, for instance. I've had them my whole life and I doubt they're going to go away with a bit of sleep.
For your forehead, It can't honestly be that bad, and when people meet you, their first impression isn't going to be, wtf is going on with that dude's forehead? It's either going to be, wow, he's funny, wow, he's a jackass, wow, he's just completely awesome, or something else of the sort. Attractiveness is as much about how you present yourself as to how you look. You could be the hottest guy on the planet, but if you opened your mouth and the first thing I heard was a belch I'd be all, woah dude. Not going there.
Cheers. ^^ Hope I helped (in which I probably did not).