I am scared of eating out because if anyone looks at me.
Sorry to hear that you don't like eating out, because you are worried that people will look at you.
If you need to inject when you're eating out, try not to be afraid to do it at the table. Probably most people won't notice anyway, but if they do and they don't like it, try not to let it upset you, they probably don't understand what it is you are doing.
If you really don't want people to see you inject, the toilets are probably the only place to use in a resturant. They aren't always the cleanest place, so make sure you wash your hands well, and try not to put your injection stuff down anywhere.