WWA,
Nice encouraging and supportive advice.
My own advice on many things in life, not just career options, supports what's written above:
'Life Rule #1 - Have a Plan B'
The 'It's OK to put all your eggs in one basket. Just never take your eyes off it!' school never prospers if you're in a job that you cannot almost completely control (ie. you're not self-employed).
As an employee, the control you have over your own career is actually quite limited and depends upon many other factors. The largest one being the 'health' of your chosen industry and competitiveness (for employees - You!) of the various players.
While oil prices are of obvious concern to pretty much everyone on the planet, they have been many time before. As have other commodities. We have survived. A saying that I truly try to life my life by is, 'Have the courage to change the things you can, the serenity to accept the things you can't and the wisdom to know the difference.' Basically, do the best you can in all situations and don't worry about things you can't control.
The wisdom bit is the hard part, but comes with experience. Of course, experience is that fantastic knowledge gained just after you needed it. Or the ability to recognise a mistake when you make it again....
No matter what happens, refer to Life Rule #1 and be the best (pilot) you can be. Barring complete collapse of the industry you are in, the best will ALWAYS get employed.
Good luck and happy trails,
Matt