Trouble with SAHM Fulfillment

My LO just hit four months and I keep thinking, "hey, it's such a short period- it'll get better!" But it just keeps getting worse. I love my LO and I love spending as much time as I do with him (literally all day, every day) and I get through the week days thinking, "well, the weekend is coming. I'll get some help or get some time to myself. Or be able  to accomplish literally something." And then my SO will end up holding the baby for a half hour and set him down to scream so I inevitably have to stop whatever task I'm doing to pick him back up. I can't cook a full meal, do a full load of laundry, try to clean.. I don't know how people do it. I literally feel so useless and unfulfilled at the end  of every single day. I guess this is just a rant. And my SO just booked a four day weekend for a bachelor party in another state so I'll literally not even have the half hour away a day from the baby I normally have for four days which is literally my only sanity. Eugh. I don't think I'm depressed but I was diagnosed ADHD and stopped taking meds pregnant and breastfeeding so my mind is always jumbled. Idk. Just a big rant. Advice is always welcome.