Oh boy do I know what you are going thru!!!!
Phoebe is nearly a year, she started this about 6 weeks ago. She used to eat 3/4 off meal of spoon and rest by finger food. She is great with FF and has always accepted new foods with delight.
Feeding time is a battle ........was a battle, changed my tatics today.
Finger food would br good for your LO as it gives him some independence, alsoletting him have his own spoon as well (sorry if you do this already). Help him to bring spoon towards his mouth, hopfully you'll get a bit more in!!!!.
Phoebe has been having chicken,sweet pot and carrot nuggets for months, also strips chicken marinated in milk for an hour pounded flat and coated in breadcrumbs (milk softens chicken) is a good FF.
I would cut out all snack in between meals or no snacks 2 before meal as LO will take snacks and refuse meal

Phoebe cut down to 2 formula feeds at about 9mths as the afternoon one was taking away appetite for her tea/dinner/supper. If I felt she wasn't getting enough milk I would give something with calcium at dinner, making up defiecit that way.
I feed her outside today on patio, change of surrondings (live in Glasgow,scotland) weather very good for a change. It worked she ate a lot more, she threw sauce everywhere and I didn't care as it was outside. I was more relaxed therfore so was she. The dogs loved it.
Fraid it gonna be around a while, try not to panic/stress, if not eating within 30mins remove food and don't offer other choices or sweet/yoghurt if meal not eaten they are very clever. Mum will still give me that yummy sweet stuff!!!!
Good luck, thinking off you tomorrow morning when my battle starts
debs