Standard Visitor visa refused TWICE based in Tax and lots more [duplicate]

I need a concise advice on my current issue. I applied for a tourist visa to UK in November to go and visit my sister and her family for Christmas, and was refused based on:

1. I said I was self-employed and stated a personal income of 150k (1.8 million per annum) monthly, but my tax paper was showing about 52+ thousand (670,455 per annum) which unfortunately was a mistake made by the lawyer I used. Such documents didn't obviously correspond.

2. I submitted a company bank statement, and there was no proof I was a sole signatory to the account.

I really needed to travel then so I quickly requested a reference form from my back which stated I am the sole signatory to the account, then went back to the tax office complained, made extra payments got an accurate tax receipt and went to the court to swear an affidavit backing up the discrepancies.

Then I applied for another application two weeks later (December) and was refused again. Here's the refusal word for word:

1. Your last application was refused as there was discrepancy in the information contained on your tax document and application form regarding your income. You have now stated there was an error in your tax document and your annual income was entered incorrectly. You have submitted a new tax papers stating your annual income as 1.8mil and not 670,455 as previously stated. Whilst I note you have submitted a new tax document I am aware that this document are readily available in Nigeria and cannot be relied upon. There is nothing from the tax office to explain why there was this error or how it occurred and no other documentation to confirm your annual income.

2. I note you have submitted a business bank statement which shows a balance of 1.3 mil, however your starting balance was just 788.890. This means you have deposited a significant amount of money into the account within a short space of time and it's not clear where the money came from. I note there are two large deposits from your sponsor who you claim is your cousin and sponsoring your trip however there is nothing to show you are related as claimed to this person. And it's not clear why he would agree to sponsor your trip. I also note he made a transfer of 5million into your account in Oct. And it's not clear what this money was for, and I'm not satisfied you have presented an accurate picture of your current circumstances. In light of the above I am not satisfied you are a genuine visitor to the UK who intends to leave at the end of your trip nor am I satisfied you can maintain and accommodate yourself.

My questions are:

1. Is it possible that's I've been banned without my knowledge?

2. How do I prove my sponsor is my cousin? I don't intend to use a sponsor at all in my next application, bit still need to respond to the last refusal.

3. How do I explain the 5 million he paid, because the truth is that money was used to pay a school fees abroad so it was transferred out of my account the next day, so it wasn't as if I used it to be running my account as regards a visa?

4. what do they mean by documentation to confirm your annual income.?

I am an entrepreneur, I deal on clothing and textiles. I have a boutique and my company is registered but it's an enterprise (was registered in 2013 (March)).

I do hope to apply again a.s.a.p. but I don't want a refusal again. Advise me on how to tackle this refusal and the necessary documents I need for a new application. Accommodation is not a problem for me because I have family over there, would love to visit this summer. But I wish to meet all necessary requirements.