More time shooting that particular gun will help. There's no problem with the Sig platform. Try to work on a surprise break on your trigger- keep your grip consistent, and keep adding pressure with your index finger.
Front sight....press.
If you are looking for some overall advice, I'd seriously look at a quality airgun. I've found the Daisy 717 air pistol to be a great value, with really good accuracy. No noise or recoil to worry about, just some quality time with your front sight. You can shoot in your garage, apartment, or condo if you make a pellet trap.
Rent a Ruger Mk-II or Mk-III. They're fairly heavy, with a generally good trigger, and the low ammo cost means you can really afford to get to the range more often.
Look into some real instruction. A good instructor is a huge advantage, and it's worth the cost. If you want to try something fun, have your instructor load your magazine with a snap-cap instead of a live round at a random point in your mag. You won't believe how hard you'll lunge forward to fight the non-existent recoil. That's called a "ball-and-dummy" drill.
Competition helps too. Nothing like a group of your friends watching you and the scores to make you focus. Find a bullseye league, then transition to bowling-pin, IDPA or USPSA.
Remember, it's not work. Enjoy it.