You are not the weakest link, you are excellent.

This company is making you to lose your confidence while you even didn't realize it. You should tell HR that you would like to leave but want to be arranged in a way you can receive employment insurance. Tell HR, without the employment insurance you cannot live and you will have no other way to survive.

Staying in this company will completely destroy you. My English has been always bad and my accounting skills weren't good neither, but I told my firms that I want to improve and I had all the supports from my employers, otherwise, I would never be able to become a professional I want, and to be respected and loved . I have terrible accents, my boss told me: don't worry, you are so good, you walked into a meeting, immediately, you can start to talk, after 5 minutes, the clients love you more than me. In fact, I am not that good at all, I just have very good supportive working environments. All of my employers and bosses encouraged, taught and gave me opportunities, paid expensive education fees for me to learn in English, accounting, assurance, taxation and evaluation .

You are very honest person with beautiful writing, you have to find a company which values honesty and hard-working.Take a break from work and make a plan. To improve yourself in a way you can enjoy it.

What I said could be wrong too, but losing this job will do you a big favor, you will be better off. Believe in yourself. ( Your English is way better than mine. Although my English is terrible, but I have to write Objections to the government, so I told my boss that I am not going to spend more time to improve my English anymore, it's not productivity for our firm. We can simply ask a girl to check that for me, and anyway, you will review it before sending to the government. That is the way we are doing it now, and we won some very difficult cases. We lose too. No big deal, move on.)

Good lucky, my friend, Every day is a new day.