10 months of exclusively pumping

So I have been exclusively pumping for almost ten months now. It's been long and hard. So much stress and feeling defeated. I'm a stay at home mom so that made it alot easier but I fear my journey is almost to an end. I originally planned to pump till 12 months because my son has done wonderful with breast milk. He hasn't been sick any (knock on wood) and he's only spit up/thrown up and handful of times. I like to believe it's the breastmilk. My supply isn't what it used to be and maybe I don't pump enough but I pump every 3-4 hours and for 30 minutes and that's exhausting keeping my son entertained while pumping since you're kinda on a leash. I currently have a few oz in the fridge and used all of my freezer stash. I feel defeated but fed is best and I'm so so so tired of the stress and worrying if I have enough, if I'll pump enough, calculating how much I have to pump each time to have enough. It's hard. I don't want to stop but yet I do. I'm so scared he won't do as wellon formula and then I'll beat myself up for not trying harder. I need guidance yet can't find any. I don't have anyone to confined in who has been in a similar situation.