The best thing you can do is apply the RICE principle (Rest, Ice, Compression, Elevation). Also taking some ibuprofen throughout the day can help reduce any internal swelling and ease some of the discomfort.
If you absolutely must play, really focus on the follow through. If you're throwing cleanly and following through properly, you aren't putting much strain on the elbow. But when you start "short-arming" your throws, you can really do some damage, especially if you're already injured.