Husband left me after he went off his meds
I am really sorry to hear about what has been happening for you. It sounds like it would be very distressing. Is there any way for you to reach out to the clinician who prescribed the meds and seek guidance from them (if they are not already aware that your partner has ceased his meds and left you)? Do you have any close family or friends that you feel able to talk to about something like this? It is extremely difficult that he has left you pregnant as well - do you think that this influenced his decision to leave?
I would really encourage you to call the Beyond Blue Support Service on 1300 22 4636 (available 24/7) if you feel able to as they may be able to offer you more specific guidance and resources.
Please do not hesitate to message back if/when you feel you need to. You may also find searching in the forums helpful to find people who have been through similar experiences.
Your situation is really overwhelming to be in and you are not alone.
We don't know much about why you two cannot get along (lets remove any form of mental/[physical illness) from your situation as it's not always the cause.
Please look after yourself, focus on you and what you need to do to look after your pregnancy and you really don't need to be putting up his bad behavior. You do not need this right now.
Please speak with a clinician if you need to for support or BB are available too.