All I've ever know is this and it's really tough trying to pretend I'm confident and have any ounce of self esteem when I just don't know how to be without him
You can build up confidence and self-esteem. It's not something that's fixed at a certain level. Lots of posters here will tell you how they've had to build up their confidence over time. You can learn this, honestly.
How long were you with your ex?
He told me what to do in every aspect of my life. I never thought it would be like this but I'm totally and utterly lost without him controlling everything
That's why you feel lost and anxious now. You've spent (how long?) with a very controlling man and now you don't know how to manage. Totally understandable, but also something you can definitely overcome. Lots of people have done it and you can too, honestly.
Remember, it's much better to be confident and independent. Even if you wanted to be with this man again, he could leave you one day or become very ill or whatever. You must learn to depend on yourself. Your life will change beyond recognition.
Why don't you start with the link to the Freedom Programme I gave you? It won't cost you anything, just time. The more time you spend working on your self-esteem, the less time you will have for your ex.
Fill up every spare moment you have with good stuff. Friends, family, support online, doing the Freedom Programme, etc. Leave no time to brood or get bored or lonely.