Secondary occupation in breach of Tier 2

[kit24]

I did a secondary job in 2017. A tutoring job for 4 months, that went on payrole and I have paid tax for it.
It was only this year that I found out that I should not have done that as it is not in my category of work and that I am not allowed.
The government website says you can do 20hrs a week if the job is in the shortage occupation list or if it is in your same category.
This can fall under secondary education, mathematics. But it was called tutoring.

In 2017 I changed main sponsor as well and my application was approved. I like to take that as, they were okay with it. As they would have rejected my application then saying I breached immigration rules but they didn't.

At this point, I need to know if I should apply at all or if I have breached Tier 2 immigration rules and there is no point in me applying for ILR ever.

My ILR is coming up this year in a couple of months.

[zimba]

Checks will be made during ILR about your employment history. You seem to have worked in breach the conditions of the Tier 2 visa and may be refused if apply