Sorry to hear about your rejection. The first thing to remember is that the vast majority of applicants do not get a Training Contract. If you think, the MC firms get 6000 applications a year, and at best, offer under 100 places... the odd's are already stacked against you.
You have done well enough to get on to a VS, again, no mean feat. Ensure you build upon that successful application for use this cycle. The cycle is back open again so you can immediately get back on the grind.
You may have seen me post about the success I've had this year. I have been very fortunate. But, this did not come without rejection. In the first year, I made 7 first-year scheme applications and only score a couple. While this was a success for sure, the most important one (CC, as they were offering TC's) I did not get. I know that feeling of rejection. I know how anxious it can make you feel when you see others succeeding. Of course, people do not post their rejections, so it seems like everyone is succeeding when you are failing. This is simply not true, I promise you.
One thing is absolutely certain though - TCLA can help you massively. There are the tools and resources that can help you succeed here. There are also other organisations that do an exceptional job in their field (think: AS, RARE, etc). The cycle is a long one, so you have a lot of time. While I'd always advise, get working on your applications as early as possible, it can be hard after feeling some pain. Give yourself some time out, but then channel that positive energy as Jessica suggests. You've achieved a VS last cycle, there is absolutely no way you cant do it again. And this time, in your interview, you will have the benefit of hindsight.
Best of luck this year. You can do it!