First of all, *hugs*

Triple P parenting stuff has a great reputation - lots of tried and tested methods for dealing with challenging behaviours. I'm looking into doing a course myself...

Our best strategies are preventative - phrasing things positively rather than negatively (Keep your hands and feet to yourself rather than Don't hit), redirection/distraction, noticing when a meltdown is coming and heading it off (food works well here!) and ignoring attention seeking stuff.

We use 'time in' (where we sit with DS in silence, holding him if we need to, wherever we happen to be, or in a quiet corner nearby, until he's ready to apologise) for physical violence - very rare here. DS is only three though and cant deal with being left. We do ignore him though - I turn away, or close my eyes! I'd ignore all the secondary behaviours your DS does in time out - but don't go back until he's quiet and calm. Talk about this when he's happy, before the time out, so he knows what to expect.

'Certainty, not severity' - so being consistent. Also, it doesn't have to be a big deal punishment - no need for yelling, a lecture and a consequence. If the consequence is to take a toy away, then just take the toy away - no, 'I told you not to.... Right, no toy for a week! Blah, blah...naughty....really pushing the limits young man...etc' lecture. A simple, 'You did.... That means no toy for two days.' That's it. Ignore any secondary behaviours - don't get drawn into an argument.

Can you do up a simple poster with one or two target behaviours, a goal and a consequence? eg speak in a polite voice. Every time you do this you get a sticker, marble rin a jar etc. 10 stickers equals whatever reward you negotiate. Discuss what words you'd like to hear/reactions you want so he knows what TO do rather than what NOT to do.

You are already doing a great job. Don't be too hard on yourself.