I’m very sorry for your loss. Often it’s the mom who is the glue in the family. When the mother passes on, the family struggles to interact. For some people, it’s less painful to withdraw from each other than to acknowledge the loss.
I don’t know why your family has deserted you so. But neither, apparently, do you. You can’t “buy” your family’s love and attention by putting yourself in financial debt. You can’t guilt them into coming by sending multiple “save the dates.” Before you put another dime into a second wedding, arrange a sit-down with key members of the family and talk it out. What put the “leper” sign on your back? Does it have anything to do with your behavior? Or do you remind them of mom too much? Or what? Once you have the answer to those types of questions, you’ll know what you need to do.
If your family has indeed rejected you, there is sadly little you can do about it. What you can do is rejoice in having found a man who loves you and with whom you can make the kind of family you wish you had. By all means, have that second wedding if it will help erase the bad memories of the emergency wedding. Let his family celebrate with you — both for his good health and your marriage.
I wish you well.