Mobile controls

Hello !
I need help.

I want to have in my mobile game to be controlled by arrows (left and right)
I am using 2 side scrolller template.

I made by my own scheme for this:

I have one issue here:
When I touch the controls, it´s working only for 1 second. Then, I need to click on it again. I need to make it like for unlimited time. I am using this for moving with my character, so that button should be possible to be hold and character will run.

Can you please give me some advice?