First, your forehead is perfectly normal.
Second, the idea that you should enjoy these last years with hair sort of implies that it's harder to enjoy life without hair. You may find that the exact opposite is true. My own personal story: I started losing hair at 19, tried to treat it, had sexual side effects with propecia and saw palmetto, stopped trying to treat and then just tried to hide it, and I did that until pretty much everyone could see that I was balding anyway. If I could go back in time, I would have buzzed it off much sooner.
I think Classfood makes a good point. Being preemptive prevents that denial/hiding from it stage during which I was anxious and self-conscious all the time. Skip that stage and own up to it early on, because trust me, once you go down that road of trying to hide your hair loss, it can be difficult to get back on the right track.
All the best,
Phil