iPhone vs iCloud Storage- nothing will work properly I am stuck!! iPhone X

So, this will probably take a lot of explaining as I'm not entirely sure what my problem actually is.

Here is some info that will probably be useful to whichever kind soul hopefully chooses to help me.

I have an iPhone X, with 64gb storage.

I am paying for the 2 TB iCloud storage plan.

My iCloud photos is turned on along with 'Upload to my photo stream' and 'optimise iPhone storage.' 'Transfer to Mac or PC is ticked as automatic.

Last successful backup was end of February.

I take a lot of photos. So I pay for iCloud storage, but whenever I try to backup my photos onto iCloud it says backup unsuccessful even if I leave it locked, connected to the internet and on charge for hours it always comes back saying its unsuccessful. (I assume because I don't have enough iPhone storage to back up)

I have no iPhone storage left despite the fact I have deleted all the apps I can bar essentials. I have taken all the measures of freeing up iPhone space (clearing caches, deleting old messages etc). When I go to take a photo I get the iPhone Storage Full message which stops me from taking photos, and alot of the time my phone won't let me delete photos in attempt to free up space either. It doesn't load any photos unless I restart my phone and then some load but only for a few minutes? things like screenshots don't save to my camera roll either.

Also, when i go to Settings>General>iPhone Storage> next to the iCloud Photos bit there is a loading sign with 1% next to it. It always looks like this and i don't know what it means.

I just don't understand what I'm supposed to do as i can't backup all my photos to iCloud so they are safe but I can't take any more pictures or download apps as my iPhone storage is full. I deleted all the photos I can without loosing memories/things that are important. What do I do?????

I don't think any of this makes sense I just hope somebody can understand what I'm saying as nothing else online has helped me. I can't go to a shop to talk to someone in person due to COVID 19 and the apple support question system thing left me waiting for hours and never got back to me. I am so stressed and my photos are literally the only thing I care about I would kill myself if i lost them. Thank you so much in advance anything is appreciated.