How to convince my boyfriend to make an appointment for his bipolar before it gets too late?

My boyfriend has bipolar and he’s been telling me for a week or two that he knows he needs to make an appointment with his therapist. But for some reason, he won’t ACTUALLY do it, just keeps saying that he knows he needs it.

I’m 7 months pregnant and over the past few days, I’m noticing he DEFINITELY needs to make it sooner than later. I’ve been with him when he’s hit some pretty deep lows with his bipolar. He’s been having a depression episode (I think it’s referred to as?) and I notice he’s repeating some of his (what I call) red flag behaviors:

*His reactions/feelings to certain things don’t match the situation and seem very extreme/explosive

*Earlier we had a small argument that he told me he was unhappy with me then retracted that and said he was really just unhappy with himself and felt like he was just a piece of shit

*Keeps telling me that he feels like he doesn’t deserve me or the baby bc of his issues

*Keeps telling me thinks he’s ugly, that he thinks his d*ck is too small, that he thinks he’s going to f*ck up our son’s life

*Has a hard time sleeping even with meds that are basically tranquilizers

When he used to get like this before, he would go really overall-distant and/or break up with me but then says he regrets it all just feels lost in his head and begs for me back. (This was YEARS ago, he’s done better since, but I really don’t wanna go back to that)