Work with a buddy at the range...find an experienced shooter ...and get some suggestions.
Read some books on tactical shooting - Massad Ayoob, etc - and some competition shooters Brian Enos, etc ....and look at their suggestions on grip and control of the gun.
Consider your grip options...and try different things - higher or lower thumbs, touch the slide or off a little , ( 70% grip with off hand / 30% with trigger finger hand ) or 60/40 or 80/20 ..., position of your elbows - are you locking out or bent a little ....foot position might stabilize you a little....lots of stuff....
But you need someone to watch and help you ...
Are you ok on slow fire / is it worse on double taps after a reload ...like tap 2, reload, tap 2 say in under 5 sec .../ are you better coming out of a holster ...or is it worse / are the sights black, or white or whatever ...maybe you need bigger sights or something easier to see / are you looking at something other than the front sight / if you put up two 10" targets a foot apart ...and double tap one, then the other ...reload ...then double tap one and then the other is it worse...
Maybe its the gun ...maybe you don't like the grip angle ...or the trigger and how it resets .. or how it breaks ...so what now ?? Do you need a slimmer grip or is that worse ...and on and on .../ different models, different guns ..that's why we all dislike some guns ..and love others ...its not a one size fits all thing. I'm not a Glock fan - it isn't because they're bad guns ...but I just don't like the grip angle, how the trigger breaks and especially how it resets ...to me a 1911, is a much more precise weapon...but even in 1911's I don't like a 3" gun...I like a 5" gun ...a 4" gun is ok. I like some of the Sigs - 239 (single stack is ok ), DA-SA trigger is ok, DAK trigger is horrible / 226 model is ok ...220 model not so much ...its all about what fits your hands / how it comes up in line to suit you ...not what suits me.