Should i be able to learn to talk again with speech therapy?

Depends: It would depend on what your speech problem is and what caused it and to what degree you are affected. If you have the ability to make speech, the therapist should be able to help you regain some speech and to have that speech be more understandable. Can't answer you question totally without more information and re-phrasing it.

Speaking: Whether or not you will regain speech has a lot to do with the reason you lost it. If you lost it from a stroke, it can take 6 months or longer to regain speech. It is very individual and depends on the area of trauma. Speech therapy is the most common treatment so stick with it and be patient. Good luck!