Hi,
your story is extremely similar to mine, and although all surgeries, recoveries and after effects are vastly different, you need to know that while it was very difficult, we survived and thrived.
i was 36 and my third child was 5 days old when my tumor was diagnosed. the first six weeks of her life were chaos as we made the preparations for my surgery and care of the children. my husband and i both had our parents in the area and as i worked part time as a consultant, we had a child care network partially in place. i was never able to nurse my daughter, but we bonded well, even with the chaos. my son, the oldest at 4 and later diagnosed with adhd and asperger's, was and remains extremely close to me. he was the most affected and confused by my surgery, but bounced back quickly to his hyper active normal. my middle daughter is the easy, sunny, outgoing child, no change there. I lived with my parents for the six weeks of my recovery - my 12 hour surgery and jumbo tumor (completely removed) - required no lifting and no stress, although being gone from my children and worrying about them constantly meant there wasn't a complete absence of stress. living with three children under 4 wasn't an option, but i had to trust that they were loved and well cared for.
i know this arrangement isn't possible in your case, but the more you can take off your shoulders now, i firmly believe, the better. My children are grown now and we still have a very tight bond. the biggest after effect for them was my youngest's lopsided smile that completely mimicked mine (hers is gone now, my facial right side, totally paralyzed after surgery has come back about 60%, which is good enough!). i was starting to get a strong feeling of continued movement when i stopped walking or turned suddenly - that went completely away after the surgery. i have ssd and extreme dry eye, and very slight balance issues but that's about it.
this is all a long way of saying, that yes, all can turn out well for your children. do your planning up front, arrange as much help as possible and know in advance that it won't be easy, but you can get through it. your life will be different, but you will find your new normal. you sound as if you can handle a lot and are a giving, caring woman. this will not change - the challenges will, but draw on your inner strength, it can take you far.