Tom, I've been playing guitar for 32 years. I have started with the basics on this site because I am self taught. Plently of things appear to be,,,challenging. should I mention scales!!!
Most new things require you to develop muscle and or pattern memory. When you are learning something new on guitar you will find your fingers go in the wrong place, you pluck the wrong string oryou muffle half the bloody strings and that pushes you to thinking that "you suck at this".
Truth is, EVERY guitar player (experience or not) has experienced that. It will stick after a while. Personally, I have sometimes found that it's better to go grab a coffee and come back. Somethiimes the more frusted you get the worse the co ordination between you brain and fingers seem to be. You will also find, on occasion, you will come back to something 24 hours later and it just seems easier- I have no explaination for that.
Hang in there brother you will master it!
Kev