Get gigs. Learn material for the gigs. If you run out of material to learn, take fill-in gigs.
I play mostly fill-in gigs. I also play in church. I am constantly learning songs. It's kind of funny. These days my wife and I will go hang out at a bar for beer and wings. I can hear 25 songs played at the bar and I have played 24 of them live. It doesn't matter what style of music they play (rock, soul, funk, country, blues, etc.), I have played most of the hits in that genre at some point. The set I am currently learning is classic rock (I already knew every song in the set) and country with a couple pop songs. In a 50 song set I am having to learn 7 songs from scratch and brush up on two more in a different key (backup or lead vocals on every song). Between now and that gig I will play five songs on two different occasions in church.
The short version is that I am CONSTANTLY learning new material, but not just at random. I am learning them for work. You will stay much more motivated if you have a goal and a deadline. Just waking up every day and saying "I'm gonna learn me some songs today" won't keep you pumped up to follow through.
Get work. Prepare for that work. Your vocabulary will grow quickly.