Things will be easy, and at other times things will be hard. Sometimes a director will say “I hate it!”. You can’t get personal and let emotion get in the way. The hardest part of the job is getting knocked down and picking yourself up. There’s no one other than you who can do that.
Keep going, and don't stop. There are SO many talented people out there and I see so many of them give up over time. No matter what it is, composing, running, flying - keep doing it and you will eventually succeed. That is literally the only one thing that you need in order to succeed - just perseverance.
Don´t ever give up and take it seriously if you really want to be successful on this. Networking is a really important but do not act like a jerk. I already know cases of people that are trying to start in the business but their names are already in the “black list” of fellow composers and professionals of the industry.