Learn English – Difference between ‘everything to me’ & ‘everything for me’

Usage of 'to me' and 'for me' seems similar, but it has a slight difference.

Usage of 'to me' is more personal. It Indicates how much a thing/person values to you.

Let's look at the following example.

The car is important to me because my dad gave it to me.

Here, it shows how valuable the car is to you.

On the other hand,

Usage of 'for me' indicates the benefit.

Let's look at the following example.

The car is important for me because it helps me with transportation.

Here, for me is used to tell the listener about the benefits of the car.

Refer this link for more information

YOUR CASE

The choice depends upon the reason for you to utter those lines.

Using to me in your case would make more sense because you are using the word everything. The word everything means that you are talking about someone you love/like (In your case). So if you want to show how much you love/like somebody, you can use to me.

When you use for me in your case then it should be followed by a benefit.

For example,

She is everything for me because she takes care of me.

Hope this helps you.