There are several things you can do, but the first place to start is here:
Reverse Engineering
If I was doing this, I would eliminate about 75% of the cross-sections. Then I would make sure each one was closed. Then I would rebuild them to degree 3 and within some reasonable tolerance. Then I would try to loft them. As a test, try to loft 3 or 4 of the cross-sections you have, just to see if it will work.
If that works, try to add a few more cross-sections.
One of the biggest problems with geometry like you have is that some of the cross-sections are either too close together or right on top of each other.