Need advice .

So my SO and I have been together roughly 4 years , we have two children (2yr old girl, 5mo old boy) we stayed together until my daughter was ten months old.. then we separated for about a year , but we still really didn't separate( I got pregnant with our son) before I got back with him ( when I was 7 mos pregnant) I found out he had been with someone else, and it completely broke me. He apologized and said he made the biggest mistake and he wanted to be back with me and our family . So I sort of started to accept that things happen and maybe he really did realize he made a mistake. We got back together, everything was great.. we welcomed our son into the world . NOW, our son is five months old . Things are weird , we rarely have sex .. we used to have sex all the time, like A LOT . He works a hard job with a lot of hours but like I need sex ya know ? When we woke up the other morning, he didn't know I was awake yet and he was scrolling on his phone , opened his browser and the last thing that he must have been on was a porn site , because xvideos.com showed up and he got out of it . I'm wondering when he even has time to watch it ? Because hes either at work or with us .. but what bothers me even more is that we aren't having sex hardly but he's watching porn ?!?! Like that makes me feel unbelievably undesired. And last night i said something to him about us not having sex and he brought up the fact that I never give him head anymore . But he never eats me out either .. and since we broke up and got back together I'm not as happy to suck his dick since he's been with someone else and I've told him that . I don't know what to do , I'm such a sexual person and I understand he works a lot and we always have our kids.. but like , I'm the type that's down to get a babysitter, go out to eat and have nasty sex in the car before we pick them up .. but yeah right . It's weighing on me .. I feel like sex is a priority because its about the intimacy, which is rare anymore . I just want the old him back , before we separated . I'm at such a loss and I'm so depressed . He's awful at communicating so getting strangers advice is the best I can do 😞 help .