Here's something that will get you some new skills to play with. This is just a McNugget, for sure not a whole chicken, but should be good stuff for you.
If you haven't gotten your bass set up, you should. It will be much easier to play. Like night and day different. A reliable guitar repair place should be able to do that for you. They will make the strings a little easier to play bn lowering them closer to the fret board, and make sure the tuning is as perfect as it can be, etc...
Always practice to a click. Like a metronome or something. Smartphones are great for that. There are a bunch that are free to download and will do the trick. This will help build internal timing and will build your ability to play smoothly.
Don't be afraid to play something embarrassingly slow until you get it. Much of what we do is rooted in muscle memory. If you constantly flub because it's just too darn fast to play "at speed", you'll have a very hard time getting a line or a lick down. Repetition is what gets that done. if you play it differently each and every time because of a flub in a tough spot, the muscle memory can't come together. Play it slow until you nail it solid. then bump the tempo incrementally until you get there. Don't make jumps too big. and don't rush it. If you can play something at 60 beats per minute, but not 65, then go to 62 bpm. If you build a solid foundation by going slowly, it won't be long before you can play it any reasonable tempo.
Arpeggios are great. Not sure if you know what those are, but just in case, essentially it's an abbreviated scale that represents the notes of a given chord. Know where the root, fifth and third are. Take a very simple tune of your choice and have a reliable guitar chart in front of you when you play along. Usually the Root (one) is the one named in the guitar chords. Play along and substitute the 5 (fifth) for the root (one). It will still work, but be a different feel. Take C fir example. The fifth note down the scale is G. If you see a C, play a G instead. The third is an E (as in C,D,E...). It will work out less often, but try it. If it its' a Cm (minor), then play an E-flat for the third. The guitarist would be playing the C,E,G simultaneously while strumming the chord.
So, play all 3 options for any given note that comes up and see what you like for the tune you picked. Here's a hack for the 5th. If you (for example) play a C on the 3rd fret of the a string, the 5th below is right beside it one string lower on that same 3rd fret. E String third fret is G... The 5th above is down the neck two frets over one string higher to the 5th fret of the D string, which is also G, just a higher G.... (as a bonus) the octave is right beside that, one string higher, 5th fret of the G string is C.
If you want a handy 3rd, it's always going to be one fret lower and one string higher. For our example, C, it would be that E on on the second fret of the D string. in the case of Cm, just "flat" the 3rd. by going one fret higher to the 1st fret of the D string, for the E-flat...
Hope this helps. There is much more to this. but wanted to throw you a bone or 2 appropriate to the size of a TB post. - Something that has helped be a lot is Scott's Bass Lessons. Scott is a good online bass instructor, He has a (not free) Practice Accelerator course that is online learning. I think a teacher that you can see in person is probably better, but my schedule is crazy, and I have found this to be a great next best thing. The enrollment opens and closes on that course, so if you are interested, you may have to get on a list to enorll later, but I'm in it right now and it's pretty good in my opinion.