Crohn's started to become better but ....

Four months ago I was put on methotrexate im injections 25 mg and a month and a half ago, I started Entocort 6 mg. It seems that they started to kick in (keep your fingers crossed). I'm tapering pred and reached today 2.5 mg. However, my stomach is in a wreck. I have had GERD and gastritis for 13 years now. I can't take it anymore. I'm nauseated all the time, vomiting and the reflux is so severe. I can feel it m my throat and it affects my voice. I already take Nexium 80 mg along with an anti-ulcer drug. In the past, when I used to have this, I would reduce pentasa (I only take 2g). I know that MTX, pred and Enocort are the cause but I don't want to reduce them. Yesterday, I was supposed to take my MTX injection but I couldn't because of stomach pain. I postponed it till this morning and preceded it by Zofran 8mg injection but it did not help. I'm really confused: Should I reduce my Crohn's med for a couple of days or take another action? My doc keeps Nexium IV for severer conditions and when I tell him I have stomach pain, he tells me you already take a very high dose and nothing can't be done more than that.
Any advice?
Your replies are highly appreciated.

ITA with Nanners.  I used Nexium for a couple of years and it just wasn't cutting it.  I tried Prevacid one week because I had some left over from my daughter and it worked like a charm.  My daughter now takes Dexalent, which is a newer ppi and much more effective for her than anything else we tried.  I do think you can try several ppis before finding the one that works for you.

Entocort should not be the cause of gastritis or GERD (although pred will do both).  I hope as you reduce the pred your upper GI problems resolve some more.