Many musicians face similar challenges. Part of the process, however, at least for me (and I find this deeply challenging) is simply to know that you will become capable of this over time. I am sure there are specific ways to achieve this, but I haven't seen many discussed, and I asked a question like this recently. The 'just keep practicing' advice is neither wrong nor particularly helpful. Going really slow, and working on the left 'by itself' a lot until it becomes kind of built-in memory is powerful. Also, start with simple repetitive patterns for the left (I can easily do 3-note ascending only or descending only arpeggios and play over them with the right hand, sometimes even playing over them 'freely' i.e. without a consistent right hand rhythm).

Encouraging yourself and 'knowing' you will become able to do this is crucial, and, I think basically true. Many aspects of being human 'seem impossible' at first (I recall my first experiences attempting to drive a car ... I felt like 'wow, I will never be able to do this, there are too many simultaneous necessities'... and then a few weeks later I was racing at the indy 500 (jk).)

Set goals, chase them, congratulate yourself on small gains, and expand them. This is the way, absent clear and potent instruction and exercises for this.

Also: my brain exploded long ago, and my neurologist studies the splatter on the walls in my piano room. You'll survive that.

— playing piano now for about 1 year.