lexapro is one of many prozac type meds, one of them, citalopram helped me a lot for my anxiety and panic attacks and I took it for several years
everyone reacts differently to them with the possible exception of family members
so these meds can stimulate 1 person, sedate another and have neither effect on a third
I think 10 is a bit too high to start on but if you are doing reasonably OK stay on it, best to take just before bed if it continues to sedate you
gradually work the dose up to say 15 then wait up to 6 weeks to see whether its going to help you, theres a small chance it wont
sadly help and side effects cant be predicted, you have to take it and see what, if anything, happens