Let me come at this from a different angle. Many people are saying it's risky because YouTube could fail (highly, highly unlikely but let's roll with it). YouTube failing isn't necessarily the point. Without a doubt you have gained excellent skills, and this has rewarded you financially. What else, asides from YouTube can you do? Are the skills you've learned transferable? My guess would be yes. In which case you already have something to fall back on if YouTube fails...your skills that got you there in the first place.
On the other hand you have 1 year left which is no time at all. The risk here is that if you quit, it could become a habit later on in life. Anything you start you could easily decide to quit 'because I've got money'. Not a good way to go through life.
Your decision...my overall point here is that don't listen to the people that are telling you that YouTube isn't viable long term. YouTube is just the platform. Platforms come and go. But you've got the skill-set.