Do you get unbelievably sore too?

I finally got to my goal weight of 120 down from 133ish back in September of last year. I am 26 and 5'2".

I will admit, 120 used to look different on me!!! So now my new goal is to be toned, firm, "cut"! And to get a flat stomach with some nice lines ;)

I am quite knowledgable when it comes to weights and resistance training, plyometrics, etc., but I have never been consistent. I can do cardio til the cows come home but I know that won't get me where I want to be. I have put myself into little programs and regimes that I created myself, found online, or did with a personal trainer. The thing is, I could NEVER stick to them because of how sore I would get.

I can do arms one day (triceps, delts, etc) and then legs the next (glutes, quads, calves, hammys) and then core another day (back, upper back, obliques, hip flexors, etc etc) and those muscles all get written off for approximately 5 days because they get SO tender!!! Like right now, my office chair might touch my hamstrings and pain ensues... I did that work out three days ago!!

I don't feel like I push myself too hard, I do the standard 3 sets of 12ish reps at a weight I can maintain form. If i get too shaky I just do 2 sets.

The real problem is that I don't want to just isolate these muscles and work them one at a time, I want to do dynamic movements that involve a lot of my body, but my back extensions work my glutes and hamstrings too which might be screaming from the deadlifts or whatever... how do you make it work????