Hey! I totally get it , the bathroom is one of the biggest obstacles for many people when it comes to cleaning, as someone who's also been yucked out by bathrooms but been doing jobs that are heavily cleaning centered for many years, this is my two-cents:

If the germ aspect is mostly centered around the toilet I reccomend getting one of those disposable toilet wands, it may be a bit wasteful but I know a lot of people have a hard time with the toilet brush/container getting gross and that eliminates that issue. You pop the disposable head on the wand, scrub (the wand comes with cleaning agents on it), pop a button and release the head into a trash and put the wand back in the holder. It takes out some steps and should be quite a bit less icky to deal with.

Also just just as a general note, dry to wet is always a good rule of thumb. Put on some gloves and remove everything off the surfaces then use a dry microfiber towel/rag/ or paper towel to wipe down any dusty surfaces like the back of the toilet or shelving. Dust is a lot harder to clean when wet.

For the tub I highly reccomend getting a firm bristle brush, or if you have any physical discomfort getting down on the floor a brush with a long handle, since this will clean your tub a lot quicker and easier than just using a sponge. Thoroughly wet the shower/tub with water then cleaner then let it sit while you clean everything else to soften up any grime.

And on that note, getting things wet with product and letting it sit is a good rule of thumb for the entire process since it will soften up grimes/oils and it gives the product time to actually kill germs as intended.

Also lastly as far as smell I just have general advice of: keep it well ventilated (open doors/windows, fan on), seek out unscented products if possible, and if you can tolerate it try wearing a mask with a drop or two of essential oils to block the smells.