I was rubbish for the first two years of playing. Didn't even have a tuner, just had one "learn bass" book but the cd was missing. I got a tuner, downloaded tabs for my favourite songs (on dial up internet, what a ball ache!) And tried to learn songs I liked. After two years I went to play with a band who were far and away miles better players than me and I was so embarrassed! I turned up with a 10w practice amp and they had pro kit, I had a list of songs I could play... Well! Playing with the band just released me. Making mistakes is fine, it's a symptom of enjoying yourself and getting lost and experimenting. I've been gigging fifteen years now, on and off, and I make mistakes time and time again! But when you play with others, that raises your level, if you listen and try to play with them instead of play your part independently. They will cover your mistakes naturally, they will compliment what you're doing and vice versa without a word ever being said and often without anyone consciously knowing. That's the magic of it.
Keep going! Enjoy it. Take lessons, but if you don't like the teacher change them. Play with others, ideally people with more experience but a good attitude. Listen to good bass music. Keep challenging yourself and come back to the stuff that you just don't quite get yet.... I'm still waiting for my week to dedicate to learning portrait of Tracy!
Keep going. Nobody was a bass genius on day 1. Or even day 700.