Looking on the internet deeply has found these results:

I have been used to it is the most popular phrase on the web.

I already used to it 1446,000 results on the web	I have been used to it 12,000,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
If that's all it is, I'm already quite used to it. I already used too much fuel to make orbit... much less break it. I already used antiperspirant on my hands. Genetic diagnosis is already used to determine whether a person has a predisposition to particular diseases. I already used up what was left of the potion Hook gave you. I realise that the Commission want to have fewer specific directives, but these products are already on the market, and many citizens are already used to them. I already used all the explosives. I already used up my phone privilege when I called you.	It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

I already used to it

1446,000 results on the web

I have been used to it

12,000,000 results on the web

More popular!

If that's all it is, I'm already quite used to it.
I already used too much fuel to make orbit... much less break it.
I already used antiperspirant on my hands.
Genetic diagnosis is already used to determine whether a person has a predisposition to particular diseases.
I already used up what was left of the potion Hook gave you.
I realise that the Commission want to have fewer specific directives, but these products are already on the market, and many citizens are already used to them.
I already used all the explosives.
I already used up my phone privilege when I called you.

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.