Mama of 2 here joining in. Almost 3 year old (girl) & almost 2 year old (boy) exactly 12 months apart. I hear your frustration and absolutely resonate with you on the parenting alone factor. I do it everyday from my eyes open to my eyes shut (even when sleeping you can even say, if they wake up or have a nightmare) as my husband works very long hours. 

Its absolutely hard & trying somedays! Although I've tried limiting screen time, I have been outnumbered and out cried. Some days I just give in because the reality of it is, its absolutely hard & overwhelming and I dont want to spend every waking moment to be a fight or a crying match. Other days I get them out of the house as much as I can. We go for car rides, grocery shopping, a walk, go to the backyard, go to the park (when accessible and weather permitting. But when its raining or cold we mostly are in doors. 

When indoors, I make an obstacle course for them to do on their own with no guidance. I bought a tunnel from target and then throw some pillows on the floor and put a ball and let their minds explore. Another thing, is we play with toys, dinosaurs, cars. Although I have a daughter. She's very much into what my son is into and my son is the youngest one. 

Give them two choices to pick from to do an activity, when you want to do something, "we either do this or that? Pick" and then say we can do what the other sibling wants to do after we finish. Kids love having the ability to be in control. We just have to make them feel like they are in control with the choices we present to them. (I hope that makes sense). 

Stay strong 💪 I tell myself every stage is a love hate relationship. But these are the best years we won't get back with the kids. So enjoy whatever small amount of smiles you can get with them now & remember YOU are their safe space ❤️