Coming to terms with Quitting

I've been BF for 4wks now and supplementing a bottle every now and then when I feel sick.I have chronic ulcerative colitis and I've had flares since 36wks pregnant. It gets worse some days and esp when she latches on I feel I need to place her down gently then run to the bathroom. It's really stressful because I have to watch my diet and I do,but my stomach is so sensitive or I feel I'm guessing what upset her...She's a happy baby with formula and I EBF my other daughter for a year and it went great...I'm just coming to terms with the fact that I need my meds so I can be healthy and take care of all 4 kids. Of course, A part of me feels heartbroken because I love the bonding experience. I don't think we should beat ourselves up when we try to do what's best for our babies but have to remember that we have to take care of ourselves too.