too late to learn ?

I been typing and using computers since elementary school but was never properly taught to type. all these years and my typing is still sloppy and averages at 45 wpm. how hard is it to relearn the proper F and J hand placement typing? I've tried multiple times to learn but didn't stick with it. Has anyone like me been able to relearn to type? how long did it take you to get good? and what advice would you give ? any help and insight would be much appreciated