how to loft complex shapes in sheetmetal in solidworks
there is no way you can form a sheet metal from that. I tried and there is no way to do it. Sheet metal loft works only as a transition between profiles like circles, ellipse, square, rectangle and other.
I tried forming a surface from the lines that you uploaded and i was successful, than I formed a solid body and I tried to convert it to sheet metal and it doesn't work. Sorry.
I take it that you want the part to be a solid sheet metal part, Not into sheet metal Components that has to be welded onto each other?
If you want components , do it the way the above engineers suggested all though i'l still play around an try to make a single sheet metal part.