I'd just bin him off I'm afraid.
You don't trust him enough to be honest with him, is the plain and simple truth. If you can't trust him then what's the point of him?
If you get back with him further down the road he's going to guess fine well what you've been up to and if you continue to deny it, he'll end up digging and digging until he finds proof. Then he'll know he can't trust you, and every time you disappear in future, or appear to have extra money, he'll suspect and accuse you of going back to sex work. Who has the energy for that, seriously?