Is this a postpartum depression thing?

Did anyone else go through this with their oldest after having more kids? I was diagnosed with postpartum depression and rage 2 months after I had my baby. Could that be causing any of this ? I never got PPD with my first baby so this is all new to me.. I have tried medication and therapy I’ve been on medication for months and no positive results.

Before I had my 2nd baby my son and I had such a good bond I was always very patient with him we did fun stuff all the time like arts and crafts play with toys together did movie nights etc (he was 2 when I got pregnant) but since I’ve had my 2nd baby 8 months ago I just feel like my son and I aren’t even close anymore. Like I feel so disconnected from him. He’s 3 now and I feel like I’m constantlyyy just losing my temper with him I’m not patient with him anymore, I’m constantly getting onto him for little stuff and getting frustrated by him often, I yell at him more often, whenever he cries I don’t even try to be understanding or patient like I used to I just immediately get overwhelmed and tell him to stop or go to the other room, I send him to his room all the time, I don’t play with him hardly at all anymore, and whenever I try he doesn’t want to which makes me not want to try, like I feel SO horrible and legit cry all the time because I miss our bond I miss when I was nicer to him idk what is wrong with me. Like I’m crying my eyes out typing this right now. He’s going through an age where he’s pushing boundaries and stuff and also acting out since the baby has been born I feel like I could have handled it better and could be handling it better if I just didn’t have another baby. I just am constantly stressed out with the baby and overwhelmed and exhausted from taking care of baby so then when my toddler does any little thing it just tops it off and sets me over the edge I feel like the baby takes up so much of me that there’s nothing left for him anymore. I get upset at him and I know I shouldn’t because he doesn’t understand that I’m overwhelmed with the baby and him acting out triggers me because I’m already going through a hard time with the baby so him acting out makes it harder on me but he’s just being a toddler and doesn’t understand. And to make it all worse I’m pregnant again (unplanned) and I just feel like it’s going to be worse when this baby is born I’m already struggling to stretch myself between 2 equally how am I going to do it with 3. I feel like I’m gonna have this feeling again but twice next time because I’m scared it will be like this with my second as well. I don’t want to lose my bond with her too. I have such horrible mom guilt for all of my kids I feel so bad for my oldest because I’m not helping him through this transition in the way that I should and being equal to him, I feel bad for my second baby because when I feel like this I feel like I’m subconsciously “regretting” her even though I don’t regret her I’m just having a hard time and also feel bad that I’m having another baby so soon while she’s still a baby herself, I feel bad for the baby I’m carrying because I also feel like I’m “regretting” him even though I don’t, I just don’t know what is wrong with me or why I feel like this. Did anyone else go through this? Does this feeling ever go away?