2002 suburban motor issues

chevy suburban 5.3. Ok, so long story short. Truck started
blinking engine light, lost all engine power, truck wouldn't
stay running and motor sounded like 2 sledgehammers
banging around under the hood. Got to oreileys so I could
code read it. Obviously just had misfire issues etc. Got it to
drive another 2 blocks to a shop. Said same thing. Sat for 5
days and was towed back to my house. Now after gun
season I can look into issues. Well fired it up so I could
bring in garage sounded the same way, same issues, then
boom it stopped, quited down, stayed running, ran for 10
minutes no issues and pulled it into the garage. Besides a
small tick it was running rpms level etc. Well open up the
valve cover, and had #1 intake valve spring broke, the
keeper valve etc also. So took the lifter arm off etc,
replaced parts, put all new spark plugs in and went to fire it
up yesterday to test drive and now like before doesn't stay
running, smoking like a s.o.b out of exhaust and barely
even ran with foot on gas. Now I'm no mechanic, I research,
youtube, grab a book if need be. Is there something I may
of done wrong putting everything back together?
Now I know the valve could possibly be bent, the valve was
up and didn't drop or anything when I opened up cover it
looked OK, I know the piston or rings could be bad which I
understand. The issue I'm having is why would it run
consistently in driveway, I mean something still wasn't right
obviously the spring was broke and not on lifter but was
way better with noise and performance I don't understand
what I did wrong. This is our only family vehicle and with 6
kids and holidays coming up I'm kinda starting to panic.
Thank you for any input into this matter.