Hi, when I started cubing again in mid-March, my average was 45 and my best was 30 seconds. Within a few days I got a sub-30 time (29) and I was completely sub 30 within half a month to a month. So I'd say it isn't that hard, it just takes a lot of practice and learning new things.
The most practice you should get, with your time breakdown, is the cross and F2L. At sub-30, my cross and F2L was about 5 + 15.
It'd be good to know how far you are in the sub-methods. Like comfortable you are with F2L, and how many # of looks in OLL and PLL.
The general rule is to learn 2-look OLL and 2-look PLL to get a good foundation for the last layer, then learn all of the F2L cases, followed by full PLL.
They say the most important thing in F2L is look ahead > turning speed, and while that is true, you shouldn't jump right ahead to it. The best way to practice F2L, in my opinion, is to learn all the cases and get them into your fingers. Once you can execute all the cases without even thinking, that's when you should start practicing look ahead. You can't think about the next pair unless you can unconsciously finish the current pair.
And about the cross, that's where you need the most work. If you solely work on the cross, you can easily and quickly reduce your time by 5 seconds. My cross, on average, is 1 - 3 seconds. This isn't because I'm ridiculously fast or anything, it's cause I can plan out a cross and do it in under 8 moves for any case.
I'm sure there are example solves or guides you can look at to help improve your cross. The last thing I'll say is try to practice your cross blindfolded. Inspect for a certain amount of time, basically memorize where the 4 edge pieces are (not hard at all!) and finish the cross without looking. It doesn't have to be fast, but if you can't do this, you need to work on it a lot.
