T.N.
I highly recommend the book Parenting with Love and Logic. They also have a DVD and Love and Logic parenting classes taught by a parent coach in the East Valley that I recently attended, which are awesome. Look at their website or email me and I'll try to get the info to you.
My 2 yearold son also got a lot clinger when we told him a baby was coming and wanted held all the time, which was very difficult and tiring for me, being pregnant. But my energy came back and he's still a little needier, but I try to give him a ton of attention and praise him for being such a sweet and helpful big brother.
Making things fun works well, but it does take mental effort to be that creative, and I just don't have it in me all the time. But it works wonders. For instance, tonight I didn't want the usual battle with dinner, so to make it fun I named out different colors that we had to eat. "Find something orange and eat it," etc. I got him to eat a little of everything and a lot of veggies that way. I gave him turns choosing the color. He especially thinks its funny when we take a huge bite and he does it too. Or I tell him the peas are balls and he's hooked. Choices also work well. "Boys who eat (or try) their dinner get a cookie afterwards," or get to play a game or jump on the tramp or whatever. Then its up to him. And if he doesn't eat much, next time he's hungry I just pull out his dinner. Anyways, I get him to let me put lotion on him by drawing shapes on him with the lotion. He used to refuse lotion, but he lets me now. That wasn't a battle worth fighting to me, but now that its fun its no longer a battle.
Brushing teeth was worth a battle to me, so I just told him I had to get a turn (I also tried to make it fun with a cool toothbrush and songs, and he gets a turn after me). I was firm and consistent and within a week he was letting me, but at first it was a huge struggle. It's their job to push the limits, so when you set a limit you've got to follow through so they learn that you mean what you say. Holding hands to cross the street was another battle, but worth enforcing. So my point is to be really consistent and follow through, but with lots of love and empathy as opposed to anger. Try to calmly enforce the consequences (I know its hard). So make sure you choose your battles carefully and enforce the ones you choose. Try letting more things go instead of making them a fight. If it's one of those days and my son doesn't want to get dressed, I don't make him (unless we're going somewhere, and then I tell him we can't go byebye until he's dressed and he loves to go byebye, so it works for him. Or just ask him if he'd rather wear his clothes or take them in a bag. Who cares what other people think. He'll catch on that it's not socially acceptable or as comfortable in the cold store without clothes). I've even let him sit in his diaper longer than I'm comfortable because he doesn't want it changed and it's simply not worth the constant battle to me. He never gets diaper rash, so that's not a worry for me.
Letting my son do things on his own works great for me. For instance, it was time to leave the pool and he wouldn't get out. I was getting frustrated and almost went over and yanked him out, but instead I collected myself and said, "Would you rather get out of the pool or have me get you out?" Like magic, he immediately got out and said, "I do it." I just started doing that a few weeks ago and it has worked like magic every single time so far. They love to try out their budding independence. Notice he had 2 choices, but each choice was something I could live with and enforce. In fact both choices would achieve the same result--him out of the pool.
Good luck. I feel for you. I was there a few months ago before my baby was born. It's an exhausting period, plus we have our crazy hormones on top of it all. Please give the class another try as it can turn out to be a positive bonding experience.