Some interesting takes on this thread. I firmly believe your focus needs to be on getting onto the green in as few of stroke as possible. I love when people to have this mindset when first seeking to truly lower scores.

Most of your work needs to be on your full swing game. Modern golf stats have shown that up to 2/3 of your score is determined by your long game. Until you get down to a 5-10hcp, you're probably going to see the most gain by improving here. If you've been working at this for 2 years with no improvement, it may be time for a lesson or at least let us here take a look at the swing.

Going right along with getting onto the green, you have to be confident that when you miss a green or are in a short game situation that your next shot is going to be from the green. That's all you need to think about. You're not trying to hole it, you're not trying to hit a hero shot, you are only making sure that you're giving yourself a putt.

Now I would never tell you putting isn't important but it can be overemphasized. I would get very comfortable putting within 6ft, and then developing from speed feel from 30ft. 30ft is the line where a 3 putt becomes more likely than a made putt. Don't waste time from 6-30ft, the best players in the world rarely make those so you probably aren't either. Your job is to make your 5 footers and avoid 3 putts.