Engine timing

I have been trying to set the timing in my 2003 Chevy Blazer for a week or 2.i found several different methods of doing it online and I tried all of them.I followed their instructions exactly and tried each method several times but I still couldn't get the timing right.my #1 piston was at tdc ot at least it should have been because I followed instructions exactly for that too.im am extremely stressed and frustrated by it and I can't afford a mechanic.why is it so hard to set the timing? My crankshaft pulley only has 2 timing marks.i aligned each mark with timing tab and also aligned the center point between these two marks with timing tab and it still didn't work.so then I tried another method.i used a piston stop tool and marked the pulley when piston hit the piston stop tool.then I turned pulley the opposite way and put another mark on pulley when piston hit the piston stop tool again.then I measured the distance between these two marks and put a third mark halfway between the first two marks.i aligned the middle mark with timing tab and engine still wouldn't start.distributor rotor is pointed at the #1 piston.i did everything right with all methods I tried and none of them worked.im going insane.the instructions made the process seem very simple but it's obviously very complicated or so it seems.please tell me what im doing wrong.im desperate.