Not coping

So sorry you're feeling like this! Have you talked to anyone about how you've been feeling? Your partner, a friend, a family member, your GP? It seems to me like you desperately need some support in your life.
If you don't feel comfortable reaching out to anyone in your life, perhaps it would be a good idea to call Mind or Samaritans. They are excellent at lending a listening ear (which sometimes might be a great help in itself!) and signposting you further.
If you want, you can drop me a message as well. Not sure if I can help much but I am an excellent listener! :)

I hope you manage to find a way to feel better! Xx

So sorry to read your not coping. Toddlers are tough!

As Paulina said, do you have anyone family/friend or professional you could offload to.

Does your son go to nursery, for a break for you, or to ask them advise about behaviour/techniques

Could you call the health visitor for support or advice

It may be good to reflect with someone what's going on, what you would like in an ideal world and how that could be achieved. It may be that you need to look at rules or boundaries, the consistency around them etc. Remember any change will be hard for all of you, and will need to be consistent by all for several days to embed. It will be tough but may help in the long term ?