Whenever I discipline my son he cries for his mother who isn't around

I am a single father to my son (8 this weekend) because his mother moved several states away towards the end of last year to live with her fiance. God that sounds awful. So for about the last seven months I've raised my son without her in the picture aside from video chats between them and his visits to her during school breaks.Obviously he misses her and sometimes has his bad days where he really misses her and he's just a big sopping mess. Well lately I've come to realize that nearly everytime I discipline him he suddenly "misses mommy" and becomes that big sopping mess.I'm really not sure what to do anymore. When he breaks rules or repeatedly disobeys, like all children do, they need to be punished but nearly everytime I do he cries for his mother and it absolutely breaks my heart.//As far as what I do for punishments, it isn't anything extreme. I'll send him to timeout for 30 minutes, no computer for a day, no iPad except to talk to his mom before bed, things like that and I very rarely raise my voice.He's also been going to child's therapy for about a month now, before anyone mentions that.//Edit: Guys, I think I just needed to write my thoughts down. I feel better. He has an appointment with the therapist tomorrow afternoon. I'll have to ask the guy tomorrow what to do. via /r/Parenting https://ift.tt/3h0K1B4