My realm just got corrupted!

Dear Mojang,                                                                                                                                            My realm has become corrupted. Last night me and my friends killed the wither and experienced intense lag once we spawned it; later on the lag stopped. I dont know if this was a part of the issue, but I feel like it bugged out my world. We've also been having trouble with nether portals linking together for a long time. My main concern is whether or not we can fix this. Me and my friends have put a lot of time into this realm so it means a lot to us.                                                                                               Your fan,                                                                    XxSp4c3CowboyxX