Here's a hint. If you're not pulling in $1,000/month from things related to your music, it would serve you well to grab all the marketing advice you can get.
Forget about doubling your fan base. If you know how to market you have a career all by yourself.
I've heard one too many artists say they'd rather try and figure out everything on their own. I don't know if it's a thing where people (mostly men) are being hard headed, or if people haven't come to the conclusion that there's no need to reinvent the wheel.
Listen, there are proven marketing methods, then there's trying to tell people on social media about your music all day.
I was guilty on this one too before, and I honestly think it's something where people are hesitant to take marketing advice because of pride. The thing with this approach is it's going to take you far far more time to figure out something someone else has already figured out.
Is it going to cost you sometimes? Yea, but honestly, who cares?
Seriously, I don't think musicians appreciate the importance of knowing how to truly market their music to make a full-time income. Once you know that you've LITERALLY cracked the code that everyone else is scratching and clawing to get.