I butchered a quote the other day when talking with a friend, but basically it goes like this: "A definition of insanity is to repeat the same action over and over again, expecting a different outcome."
If you're working at your game yet not scoring (or enjoying the game) as you believe you can, perhaps it's time to change up the equipment?
Previous poster hit lots of nails on their heads. I'll offer a few thoughts based on my trials & tribulations.
Gotta hit greens AND get within 15 ft or so consistently to score well, which for me means shooting in the 60's. (I'm not one of those highly-skilled Legends shooting sub-60 rounds, just an average player who is getting better thanks to equipment suited to my game, and a renewed focus.) That means dingable, accurate, high trajectory irons. The K15 irons you use do not meet the criteria from what I can tell.
I can highly recommend the L59 G20 irons. The meter is not fast. They provide a high trajectory and some holding power. These qualities allow one to target easy pin placements. From what I've seen, plenty of folks use them right up to Legend tier.
I was working my way to the L83 G20 irons when WGT came out with the L79 RocketBladez irons. I rented them. Their performance was amazing. I decided could handle the faster meter. So far I am pleased with them.
I refused to listen to the proponents of the 3 wedge system, to my detriment. Yes, said proponents are inevitably top flight (no pun intended) players. But I'm an obstinate guy. Anyway, I finally tried it, acquired three CG16 wedges that fit with my irons yardage-wise. The game I play now is so much better, I cannot believe the difference. In some situations, I almost prefer to miss greens on approach because I have such high confidence in my wedges getting me inside 4 feet for par. I won't ever insist I know what someone else should carry in their bag. Just sharing my experiences here. (PSSSST - 3 wedge system is the way to go, buddy). ;-)
Which brings me to the final piece of the puzzle - once inside the scoring zone.
I love my putter (L44 PING Redwood ZB). Through tons of practice and learning greens, I'm sinking many more 1st putts (ignore my stats, all my rounds - except Uneven Lies - are ranked, so practice rounds of which I mostly play count in my stats, skewing the heck out of them). I don't have the money to purchase equipment, so I can't provide recommendations on the qualities of various putters.
If you have the money/credits to upgrade without a worry, then set aside some time and get to renting equipment.
If you are limited monetarily as I am, search the forum (is the search function up and working?). Also, when I play Alt-Shot, I ask players their opinions on equipment. Some folks are happy to share their experiences. You might do the same.
Good luck to you!