Desperate for progress

I need some help or advice from you all who have gained wisdom over time! I'm panicking and not sure where to turn. 

My husband finally got diagnosed last week (it's been years in the pipeline). I'm 34 weeks pregnant with our second and I have a 2 year old (who has had a lot of behavioural issues).

I carry the whole family and I'm soo terrified of what's going to happen once this baby is born and if I'm going to be able to cope with still doing everything or it's going to finally break me/us. We have no family support. Im trying to put together some kind of support plan for myself (our first 2 years with our son were so so tough) but my husband seems to have no warning lights going off in his head. The medication seems to be working but only during his working hours and he's right back to not knowing left from right when he's around us. So many careless mistakes, not taking responsibility even for himself and so much defensiveness. 

We've tried so many different therapists over the 10 years we've been together - couples therapy, individual anxiety therapy etc. but he just doesn't implement the strategies/follow through. He seems to know what he needs to do in theory but just doesn't do it. He doesn't input into our marriage, doesn't step up to parent our son and just struggles to keep up with daily life or manage himself. I just feel like I can't rely on or trust him anymore. I'm so so exhausted from being let down and having to pick up the pieces after the things he does multiple times a day whilst juggling everything else on my own. I just don't know how I can keep going like this. But I've also got no other option it seems. It's maddening and I have no one around who would understand. Please offer me some wise words