Sometimes opioids can have a paradoxical effect and cause stimulation. Oxycodone is most commonly known for this but who knows, I mean you only took 60mg of codeine, that's such a small amount it doesn't really make sense.
You should definitely stop taking opioids since you probably still have the chance considering the dose of codeine you're taking. Save yourself a lot of trouble just by giving up opiates and never looking back.
Listen to Tricomb. Opiates basically always end in one of three ways.
a) You are the VERY VERY small percent that can just use them occasionally.
b) You start using them here and there, and although it sounds far-fetched, you eventually move up to oxycodone or a harder opiate, and then eventually you try heroin because it's way cheaper and you "just wanna try it once", and then eventually you begin injecting it because again, it saves money. (This is the addict thought process, you will spend more money on opiates once you start injecting then you ever did before) This is a lot more common then you probably think. Being an addict brings you pain that you can never imagine. It will put you in the worst and darkest place mentally, and will make you more depressed and hopeless feeling then anything you've ever experienced in life. And it's a reality.
c) You do the above, and either end up dead, in jail, or try your ass off at staying sober in recovery, but forever, you will be an addict and will have that little voice in the back of your head telling you to pick up and do "just a little bit more" one more time.
I know, opiates don't seem like a vicious drug when you start them. But that is why they are so addictive. They start off with seemingly little or no side effects or comedown, and for most people provide a nice blanket of euphoria and confidence and happiness. This doesn't last forever, and you start chasing the high big time, and once physical addiction starts, you are so completely fucked because you are already in it deep, and chances are this whole time you have been telling yourself you have it under control, rationalizing your use. They are very insidious like this, completely taking over logical thought process and rewiring your brain chemically.
"Oh I don't even get withdrawals yet, I'm good. *Sticks needle in arm*"
"I have it under control, I just chip. *Sticks needle in arm*"
I know this sounds a little farfetched but I started with codeine and ended up a junkie like all the rest for a little while, I'm hoping I don't relapse but it's hard as hell when you know what opiates feel like, especially IV opiates. Your life will never be the same once you start opiates, run, and run fast.