Houzz user, if I was you I would take the plant to the neerest nursery or garden centre and ask for help.

If its not getting enough light and warmth..then it cant use all that water. To me,it looks in plenty good condition. Just stop with the constant watering,trim off the worst leafs ( those ain't so bad,but if it bothers you, remove them).

If its a secondary problem,like you have bad salty tap water..then use bottled or distilled water.

About 30% - 40% of the leaves are turning brown, perhaps the pictures do not do justice but the plant is dying.

Interesting comment about the sun and water photosynthesis,, makes sense.

I'm guessing there's no way to save it as it's still sliding in a downwards trajectory health wise

Its summer. If it cant recover in a bright shady spot outdoors now,it was a lost cause.

You just assume I live where you live or something?

If you live in the northern hemisphere,its summer. Unless you live so far north,its not worth outdoors ( cold nights?)

Yes I'm in Ontario it was 9 degrees at night in the beginning of the week and 15 degrees - 20 degrees during the day

Try the House Plant forum. This forum is designed for edible figs and not house plants which is what you have. They are very good folk over there and should be able to help you.

Ok,you live in San Francisco north-lol. Where even in summer..a tropical plant survives but never gets the summer heat like the rest of the country gets. Why I knew you must have cool nights.

You shoulda seen this tree when we bought it. Omg the beauty....now it's literally 50% the fullness

Maybe a photo of the room might help. I saw in a Berkeley bookstore that had this small 3x4' skylight in the middle, a Fiddleleaf fig that was in a pot and with just a single trunk- no branching at all- reached up to the second story. Amazingly that Ficus was coated in grey dust!. Almost more dust color then green.

Very bad lighting but the only place for it. The shadow is very blurred meaning the light is crap, or so I've read