Okay I'm not the most experienced level maker here, but I do know what your problem is. The level isn't on the level select, in order to play it in srb2 without doom builder is to use something called extendable wad editor. You will find this on the wiki. Then you have to figure out how to make level headers on the wiki, copy what it tells you to copy, paste it onto a notepad document, add it into your levels xwe file within something called a MAINCFG that's the main configuration file, it allows you to do all sorts of stuff to your level, you can change it's name, the weather, and get it on the level select, just go to the level header section of the wiki to learn about what to do. Or I could just do it, just tell me what you want. I have debugged other levels, well one level.
Debugged Levels:
1: Tailzdudes "Water World"
So just tell me what you want to do, I'll even put some notes for future use, because I'm cool like that, anyway I'm here to help. Just be on the lookout for my beta demo coming soon...