Newly single mum needs advice

Hey guys, I recently split with my partner but we have a 7 month old son together. We have been together for a few years and out of the blue he wants to break up. We still live together and for now he’s on night shift so I don’t have to see him that much.

However, I feel depressed trying to cope with a break up and look after my son. I found out he’d been talking to another girl (who was his apparent best friend while we were together) and from what I could gather she had been very rude towards me, calling me names and insulting my parenting etc and he didn’t even try and stick up for me. I get we are broken up but it feels so soon (it was the day after we broke up he starting messaging her but I think it was before honestly) especially because he was still sleeping with me and being lovey( I only allowed it because I thought we would get back together as we have fought in the past and made up) . I’m not sure what to do as I am a SAHM and I have no where else to go. He says I can stay in the house until I can sort it out for now but honestly I’m just so depressed. I feel like I have been half cheated on and betrayed. Looking after my son is a struggle as I’m constantly feeling like shit or having a breakdown. I take care of him but as soon as he’s down for a nap I find myself in tears, my house is a mess and I feel too depressed to do anything. I recently recovered from Postnatal depression so that doesn’t help.

Any advice is much needed x