Old house , clogged shower. HELP!!

I'm renting a small house that is over 100 years old, but has PVC for the drains, and recently the shower drain has been acting like its possessed. It first started as just a slow drain and then began to clog completely. I would flush the toilet and it would gurgle and fill with nasty water, I would use the bathroom sink with the same result. Suddenly the toilet stopped effecting it, but the sink closest to it still fills it with nasty water. I've tried Master Jack and it just made things worse ( and nastier ) I've bought a snake but can't seem to get to the clog, it just stops dead 10 ft in. What do I do? HELP!!!

The landlord needs to call a drain cleaner or a plumber who is experienced in drain cleaning to snake the line. You need to the proper equipment and some experience using it to do a safe, effective, and thorough job of cleaning a drain.

I'm trying to avoid that route, considering I'm on low income. I've heard the vent pipe on the roof might be clogged with debris and snaking that might solve my problem. Is this a viable option?

You mentioned that you are renting the house. Normally, clogged drains are the owner's responsibility, unless it can be proven that you have abused the drains by introducing things that shouldn't be.

A clogged vent is rather rare, and almost never the cause of a slow drain.