At wits end with 21 month old?

Don't give in to him. Just because he wants to be held doesn't mean you have to.

Set rules for him and be consistent. He is just wanting attention.

Get him involved with laundry, dishes(plastic stuff), making dinner ,cleaning,etc...

I hate to sound harsh but your attitude about the whole thing may be the problem. Instead of looking at how annoying it is for you, maybe ask yourself what need your child isnt having met that he is having to beg for your attention. The best way to get things done with a toddler is to have a routine. Have a similar schedule each day so that the child knows what to expect and alternate between together times and independent times. When he wakes up, have a good cuddle and talk about what kind of day you are going to have. Get dressed and give him breakfast. Get a little done while he eats breakfast. Do a 30 minute activity together. Go for a walk or play a toy together. Then give him a table activity. Sit him at the table or high chair with something to occupy him. Crayons, play-do, etc. Get a little more done. Then let him have some tv time, get more done. Lunch time, read to him, nap time..get more done. Your child is probably just bored. Guide his attention towards activities to keep him occupied and you will get a lot more done.

My youngest, who is 2, is also very clingy. He would love nothing more than to be held all day. What works for me is whenever he comes over to me to be held, I pick him up and give him a big squeeze. I say something like, "Oh, I just love you!" If I really need to get other things done then I hold him for maybe 30 seconds and say something like "I sure do love holding you, but right now I need to put some clothes in the wash machine. Do you want to help me?" And then I put him down and start doing what I need to do. I've found this is better than actually telling him something like "No, I'm not going tohold you", which usually makes him even more clingy and turns into a tantrum. Instead he knows I love him, I've held him, and I get my stuff done. With little kids, I think it's all about wording things in the right way.

And what do you usually do when he cries? Pick him up? He's learnt that everytime he cries he'll get picked up. If nothing is wrong with him & he just wants your attention it's ok to leave him cry. Also, pick him up & cuddle him when he's not crying too, this should help him learn, good luck :)

Let him cry. If you know he's not hungry, not in a dirty diaper, not in pain, just set him down and tell him to play with his toys.