How can I reduce swelling and pain from my face after a tooth abscess?

Use antibiotic and. Moist heat over the area involved.
Antibiotics and time. If you had the appropriate treatment for an abscess, it may just be a matter of time for the swelling and pain to resolve. If either root canal, extraction or periodontal treatment was completed, and you are likely on a systemic antibiotic, it can take up to a week or so for noticeable swelling to resolve. If this has already occurred, i recommend you contact the treating dentist for a follow-up.
Depends. Your question is a bit unclear since it doesn't state whether you have been treated or not. If you have not been treated then the underlying problem must be addressed and treated. If the abscess has been treated by either root canal, extraction, or an incision and drainage then you need the appropriate course of antibiotics, along with warm compresses and time.
Call Your Dentist. Antibiotics may be advisable ... Aleve, (naproxen) advil, Motrin or for more holistic patients arnica can help reduce swelling & pain. Call your dentist for help with pain and swelling as it can worsen and cause other issues.