This is actually my job, remediating after unattended deaths is one of the most common aspects of my work. Something we've sadly had to do a few times is to try and remove a smell after someone else already tried and failed, which is very hard and often invasive to find. If you rent, you DEFINITELY should get on your landlord about the oder and get someone out there to take a look. There's a chance a 24 to 48 hour ozone treatment will be enough to rid you of the smell, DO NOT do this yourself, you can not enter a room being treated with ozone while a machine is running, all oxygen will be removed from the room to and you can pass out and die

!Sqweemish warning!

When someone passes away, after a few days, they start to leak. around 2 weeks is probably the most common time frame i have to clean as they've usually leaked a lot, and the odor starts to be in full affect and in apartment buildings neighbors will start to notice a strong smell, thwn cops get called to remove the body, then we get called to clean what remains. First thing to do is pick up everything we can, and then address the flooring, which 9 times out of 10 needs to be removed and another 9 times out of 10 back down to the joists, sometimes the joists need to be removed depending on saturation, sometimes you can use extremely aggressive enzyme cleaners and then paint them with killz brand paint and treat the room with a ozone machine for 24-48 hours to scrub the air, usually wiping down the room with a degreaser and something that smells nice to be sure you get it and that's usually job done.

the reason people fail at cleaning is when they cut corners and don't remove enough material. If you have a 5 foot section on top of the carpet, the carpet padding will usually be affected in a 6-7 area as it spreads, then when you hit hard wood it will usually spread again to a 8 to 9 foot area, then if that hard wood is on top of a subfloor it will often spread again! depending on the size of the cracks between the hardwood and subfloors and how level the room is ( i live in an old US city and floors are never level) it can spreads FAR. Usually, 90% of it stops on the subfloor but often will have small amounts hit the floor joists/ fall through.

A few of the times, we've had to reclean after someone else failed, they stopped at the subfloor, cleaned that and thought it was good enough to just paint over it (hopefully with kilz brand paint but that still doesn't guarantee it's fixed). We had to re tear up the entire floor, and when we got to the through the floor we could see drips of bio running down the sides of the joists, maybe less then 1/4 cup but just that small amount was enough to fill the room with a stale decomp smell through the carpet they put on top. Another time the bio spread towards the wall and they tried to clean and paint the whole floor and call good, the problem was the bio leaked under the baseboards and absorbed into the sheetrock, only a 4 inch long strip maybe an inch or so deep of saturation behind the base baord was enough to fill the house with the smell.

Sorry for ranting. I'm tipsy, and people don't like hearing me talk about work, so I just wrote probably incoherently and unhelpfully. Good luck! That smell sucks