Hi there ep1977, my 3.5 yr old gets really violent when he doesn't get his own way - have you got the New taming toddler book by dr Christopher Green, it is a good read, particularly for LO's at this age...
I have a couple of really good friends who I met when we were all pregnant neither of whom have experienced the a ount of hitting and biting and kicking that our boy does, so they think it's weird and ossibly only child syndrome which did make me question whether we were doing something wrong with ours but I recently met a couple of mums who have both said (thank god) that they have exactly the same problem with their kids which made me feel so much better! You are not alone, even though you might feel that way right now, I promise!
You are most certainly not to blame either - I get the impression from the toddler taming book that most toddlers go through the testing phase (acting out when we say no, to try and get us to give in) and some toddlers are more likely to find the buttons to push because they think it will make you give in faster.....which for us is always when we're tired - we tend to get angry and shout, then give in because we're too drained to carry through with the discipline - he knows this by now, so does what he can to make us angry quickest (kicking, hitting, biting etc..).
I'm finding that the only way through is to stay completely firm on discipline (naughty spot or silly step, courtesy of super nanny!) works best for us. It doesn't stop him doing it again, but the frequency certainly lessens the more we follow through because he knows what's coming when he's threatened with it. Counting down seems to work more often than not (if you don't stop hitting mummy by the time I count to 5, you'll go on the step - or enter your disciplinary measure of choice!). Sometimes I do take the easy way out and use 4 and a half, 4 and 3 quarters etc.. to try and avoid the discipline, but I know that's something i need to stop doing so he's not let off the hook as much.
The worst bit is that you feel like your being 'bad mummy' by being mean all the time, but I have found that soon enough, my Lo has learnt that I am more likely to follow through on discipline so is less likely to hit out at me. Daddy is another story though... ;o)
Having said that, I'm not out of the woods yet, of that I am sure.
I'll keep you posted, sorry this is such an essay, can you tell I'm new to this?! Good luck, let me know if this is helpful at all, I would love to know how you get on.