Omeprazole Poor Choices, Carditis, Zantac, Gingerbread Man, Little Kid

Okay everyone, I need help. I have read all these posts and I am beginning to think I am not some crazy mom. My son is has just turned 5 in November has been on Prilosec since August. before that he was on Prevacid off and on his whole life. When I say off and on I mean on for a few months off the rest of the year. When he is on it, he seems aggressive, moody, tired, not too interested in his karate or school (which isn't like him), very short tempered, and recently overly concerned about death. He doesn't complain about physical symptoms but I notice a HUGE change in behavior. He hits his brother hard over the littlest things. He is making poor choices at school, like hopping a fence to catch a gingerbread man (LOL), or throwing food. He seems harder to get to sleep at night and impossible to wake up in the morning. He will scream if he gets upset. I know it sounds like I have this horrible child right? Well let me tel you it had been a full 18 months in August since he took any meds for reflux. Yet Dr diagnosed him with reflux carditis in which reading I guess is a controversial thing right now (thank God, maybe he is not as bad after all). But with that diagnoses lets face it we are nearing potential cancer. I am terrified to keep him off meds but I am not sure if him being on them is right either. This is a very happy little kid. He is VERY smart and outgoing. Off meds he is very well behaved, yes he does make some interesting choices, yet never aggressive. He became very aggressive and mean after August and I blame the meds. He also take Zantac 75mg before lunch ever day. Do you all think the Zatac should be enough or both 20 mg of Prilosec and 75mg of Zantac should be what he takes? I think that is way too much for him. I am okay with the Zantac but I don't know. I do know one thing and that is I NEED HELP. Do you guys get angry more often the meds? which meds make you worse, the Zantac kind or the Omeprazole?
A very concerned mom....