Weaning!

Please tell me someone else has had an extremely hard time weaning their baby! In all fairness, I've only been trying for a week, but he is resisting it completely. I'm currently trying 1 feeding a day. He is fine with a bottle as I've been bottle feeding expressed milk since birth. I thought it might be the kind of formula I was using, but I've switched brands and he isn't responding any better. I've tried mixing 75% breast milk to 25% formula, but he still pulls away screaming. The only way I have any luck is if I feed him while he's nearly asleep (which is not a habit I want to form). I know babies won't starve themselves but he cries and kicks and screams and refuses to eat until I the next feeding time when I offer the breast. As his mom it kills me to see him that way.

I don't have a choice but to wean him as I will be leaving the country for 10 days in May and leaving him with family and there is no possible way for me to pump enough to support him while I'm gone. I am open to any suggestions you may have! Thanks ladies! This is so much harder than I expected.