Why won’t the good days last??!!

Just when I was about to post Johnny’s update on the “Hip Hip Hooray”, he rejects his bottle and throws up on solid again! 2 weeks ago when he was discharged from the German hospital, he was doing so well (taking 25-30oz of formula from the BOTTLE!) and continued eating well for about a week. And then for some unknown reason, he started to take less and less until today—he completely rejects his bottle again! I had no choice but went back to the painful spoon-feeding, and he vomited big time! I really don’t know what’s going on with him! He was referred to see the German GI specialist 3 weeks ago. I was hoping that the doctor would be able to prescribe Motilium or some safe medicine to stop him from vomiting. However, as soon as we saw the doctor (she is not a GI specialist at all, just a regular pedestrian), she told me that Motilium is no longer available in Germany, and they usually don’t give medication to babies with reflux. They are strong believers that diet (i.e. thickened formula or solid food) is the key. I wanted to go home since they couldn’t/wouldn’t prescribe any medicine to help Johnny’s excessive vomiting but was convinced to stay and worked with the experienced nurses to change Johnny’s terrible eating habit (exclusively spoon-fed with DVD on). On our second day in the hospital, both Johnny and I got very sick. We had severe stomach flu & was throwing up none stop! Johnny was on IV for 1.5 days and lost half of a pound (As a FTT, it was a big deal!). Miraculusly, during his recovery from the stomach flu, Johnny gradually took the bottle again. After a few days of trail and error, we finally found the formula that he would take the most. Surprisingly, it wasn’t any hypoallegic formula or none-milk base formula; it was just a regular German formula flavored with banana taste. Johnny loved it and did not vomit on it at all! Well, as said before, it lasted for only about one week & he slowly showed his dislike to the formula/bottle again. I suspected it might have something to do with Zantac and his weight gain. I increased his Zantac (2.1mlx2/day) dose & added Prevacid (7.5mgx2/day). It’s been 6 days, but things are just getting worse and worse. I know it takes some time for Prevacid to kick in, but I am so worried that Johnny may his hard-gained weight before then. I also have no idea if he will eat better even after Prevacid takes effects. It’s 5pm here and he has only had 5oz of formula (with force) so far. He cries when he is hungry but pushes the bottle away and falls asleep (dream-feeding doesn’t work on him either). He sleeps well and longer and shows no sign of fussiness. I really can’t figure him out! Any idea/suggestion will be highly appreciated? Urhhh…..why did my good days end so soon???!!! When will he outgrow this???!!!