My cockatiel keeps either regurgutating or vomiting?

My beloved male cockatiel, Jo-Jo keeps sneezing and either regurgitating or throwing up. He's literally like a brother to me and my parents got him just before I was born (I just turned 18 in May.) I don't know what to do! I'm certain he's just regurgitating because he pumps his head before it happens, and he eats and drinks, and his color and eyes are fine. but he's been doing this for almost two weeks, several times a day. When his seeds come back up they're whole and undigested. I just gave him some organic and freshly cleaned lettuce from my garden, and he's been eating it. Also, he only goes to the bottom of his cage to chew on clean paper and then he comes right back up. Please, can someone tell me if there's anything wrong with him? I can't imagine life without my little brother in it, and I know he's old but he's usually very healthy. I always have my phone on me, infact I typed this on it... so if you could send me an email letting me know if he's alright. I don't know if you can get my email without me typing it but it's Kira_Mia_Blood@yahoo.com.... Please help me! Joey's life matters to me more than anything, including my own life. So please, please help! Thanks...