then why are you expecting yourself to make comics that last over a year? comics dont need to be longrunning, you can make a 20 page comic in a month and then be done with it.
i actually recommend you do try something significantly shorter, bc carrying a project from beginning to end makes it a lot easier to complete future, bigger projects. finishing something is an important step for any storyteller.
you sound burnt out. in this situation you should honestly take all pressure off yourself to create - youre putting all your energy into work, and you deserve to rest and do things that bring you joy when you come home. if right now that isnt art, then it isnt art, thats fine. just find a way to unwind and enjoy your free time.
and i know its not always possible, but if it is, maybe you can look for a less stressful job? it sounds like its distressing you a lot. im not saying quit ofc, as you said thats not an option, but maybe browsing for something that takes a little less from you is possible. i dunno your situation though.
honestly, ive heard this exact same sentiment from people with very successful years-old webcomics. its pretty natural? when you get to the end of a big, long project youre a very different person to who you were when you started, and your reasons for making work change. but the difference between you and the people ive talked to is their old comics are paying the bills - what youre doing is for free and for fun. your enjoyment of it is the #1 priority.
are there any places in the story you can edit down to get to the end faster? i think if youre close to the end finishing this thing is a good idea, for your own satisfaction more than anything, but do not over exert yourself. your audience will be patient. dont be afraid to make changes to your comic to make it easier or more enjoyable to work on.
although maybe before that, since youre very clearly burnt out, put it on hiatus for a month and just focus on regaining some energy.