Okay, I looked into my old hacking download files and found an older build of your game What a Blast.
I made a patch for it (untested) open it up in lunar magic after you repatched it with SMW and see if you can't start from an older stable build.
Also you can always just finish what you currently have. You don't have to go crazy and make it super ambitious to the point that its too hard to complete.
All I'm saying is give it another shot man.
I used to use Hyrule Magic in the past and that program is notorious for messing up your rom so Zelda 3 hackers know that you have to make lots of backups. So when I did my SMW hack I made backups everyday that I worked on the project. For my SMW hack I have 170 backup copies of the rom to be exact.
All I did was create a folder named "backups" and just copied the pasted my latest rom in here. Windows automatically renamed them for me because I said yes keep the copy of the file even though the name is the same.