1995 Toyota 4Runner Hooked up jumper cables backwards

So I had a momentary lapse of common sense and hooked my jumper cables up backwards (I've jump started cars dozens of times I was just in a rush) by the time I noticed it I went to pull the cables off and sparks flew and the battery was toast (almost melted the positive post) so I replaced the battery and nothing, no lights no power at all. Upon some inspecting I found the main 80a fuselink was fried along with a couple 15a fuses. So I replaced those and now I have power but the car won't start, I turn the key and nothing happens. I really can't afford to bring it to the shop. Anyone have this happen to them before. I think it's either the starter motor or the ECM computer. Any help would be really awesome!

Also how can I test the ECM to see if that's the problem Cuz they're expensive and I really don't want to replace it if that's not the issue