Mac not syncing with iPhone/iPad

Can someone help me? My Mac is acting up. Over the past 3 days, I have not been able to get my Mac to sync with my iphone or ipad like I have in the past. When I open up my calendar on Mac, it says it cant be refreshed and won't let me do a thing until I force it to quit. I input things on my reminders and notes on my Mac but it won't show up on my other 2 devices. But if I put stuff on my iphone/ipad it will show up on my Mac!? I've tried updating, shutting down, connecting with a USB. I don't know what else to do. I really don't want to have to delete all my stuff because its a lot! Help please!