Being a music student isn't like being a engineering student. There is not a job waiting for you automatically as soon as you graduate. This can cause a lot of anxiety as you wonder if you'll be able to support yourself, pay your student loan, buy a house and a car etc... That kind of anxiety can be a poison for your playing and for your life in general. I could give you all the "believe in yourself" and "don't give up" clichés but instead here's a little story:
Many years ago, I met a director at the CBC radio who use to be a music student in college. She had just started to play horn again in a community orchestra where I went to help for a concert. Things didn't go very well for her in university. Although she was passionate about music and determined to make it as a musician, the pressure and the competition got her frustrated, discouraged and depressed. No matter how hard she was trying, things just didn't seem to work.
One summer, she found a part time job as assistant radio-director. Because of her musical knowledge, she did really well so they kept hiring her occasionally after the summer until they offered her a full time position. She was later promoted to director. She is very contented with her career, has a more than decent income (as I could tell by the car she was driving!) and enjoys life very much. After a few years, she picked up the horn again and enjoys playing music in a community orchestra.
There are thousands of stories like this one. My point is that even if you don't win a job in an orchestra, the musical knowledge, skills, discipline, work ethics and contacts that you acquire as a music student are invaluable assets that can help you in the music business or in any other business if you are willing to be flexible about your career goals. No matter what happens, you are not wasting your time.
Some of my former classmates in the conservatory now have a position in an orchestra, others are teachers and freelance musicians. Some of them are in the music industry but aren't necessarily playing or are doing something else that has nothing to do with music. As far as I know, none of them are unemployed and none of them regret their experience as a music student.
The truth is that not everybody will win a job in an orchestra. The good news is: it's not the end of the world! Those who have the talent and motivation to win a job will win a job. The others will do something else musical or not and will be perfectly happy with their lives. There will always be places for people to play as amateur musicians which can be a lot of fun too.
I want to make myself clear here. I'm not saying that you should give up right now if things aren't going well. Far from that. What I'm saying is that there is a life outside symphony orchestras and that should you not make it as an orchestra player, there is certainly something else waiting for you in which you can be perfectly happy and make a decent living. So no need for that poisonous anxiety.
You made the choice to be a musician and that choice will bring you somewhere. Not always where you thought it would bring you but somewhere nice! So with that in mind, enjoy your playing and don't worry about the future. Your efforts, commitment and discipline will be rewarded in some way. Orchestral or not!