Need serious parenting advice PLEASE HELP

Here is exactly what happened, an unbiased story. Helpful advice is appreciated please

I have a 2 year old, 10 month old and am pregnant with my 3rd. My two year old just started temper tantrums this week when I pick the kids up from daycare. He ran up and down the halls so I had to chase him while carrying my other kid and their things plus I’m pregnant. He threw himself on the floor so I grabbed his arm to get him to stand which he refused to do. I put my 10month old down so I could pick up my 2 year old then get my 10month old and their things all while the front desk lady is watching (and JUDGING) instead of possibly helping. I am so beyond frustrated and stressed that I walked out of daycare and said I fucking hate my life. Then in the parking lot my two year old gets out of my arms and starts throwing another tantrum where he’s laying down in the street so I get him on the sidewalk and spank his butt 3 times in a row and said ur so fucking bad! (Yes I know it doesn’t help that I’m cursing but that’s my personality and I’m beyond stressed at this point). And it really doesn’t help that I’m big and pregnant and do you know how heavy two and 10month olds are? So that’s what happened. I ask Facebook hey what do I do in a situation like this how do I fix/avoid this? Some said bring the stroller in but my double stroller won’t keep my 2 yr old strapped in since it’s the Sit and stand so that’s not an option. So the next day I pick them up and I bring a child leash my mom bought me off amazon the other day and knock on wood he thought it was a game and didn’t give me trouble. Then today I get a call that the daycare called cps on me. I am embarrassed, upset, confused, and angry. So that’s what I’m dealing with now in my life. Let me add that these past couple months I have been severely depressed but have been getting no help from anyone or any program even though I reach out. I’m in the military working full time and my stress is mainly from the bullshit I deal with at my job. Dealing with my job all day then getting the kids and dealing with them all night...getting them to bed by 8 then cooking myself dinner and showering I’m in bed by 10pm if I’m lucky just to get up at 4am for work. It doesn’t help I’m not a morning person and I’m not getting enough sleep. To make my situation better I’m just ready to not be working full time. I have 3-4 more months left and I’m not sure I can make it. As I can’t possibly tell my whole life story I’ll tell you that yes I’m dealing with depression but I am an amazing mom who was stressed and was having a bad day which I thought of it as discipline instead of abuse. I have and will never leave a mark on my kids so I don’t feel guilty about anything. I have an appt with cps on Monday so I will explain my entire situation. I looked on google how to discipline a toddler and I’m still having trouble. He turned two last week. He’s so smart but still doesn’t understand. When I got him today from daycare we got in the car and he threw a tantrum because there was an old bottle of milk in the car he wanted to drink. I explained to him “no it’s yucky it’s old it’s curdling see?? You will get sick if you drink this, we will get milk at home in a few minutes” he threw himself on the floor of the car and continued with his tantrum. Please no negativity, constructive feedback is what I’m needing. Thanks.