Sus firstly
but then
I really think you need to take some action here.
Is this the tosser boss that is doing this?
You need to do a little business resourcing plan which coudl show how this workload could be shared out amongst the team, not just dumped on you. Ie you need to bring a solution not just a problem, up the chain of command to your bosses boss.
They can't change your work location without some kind of negotiation I would have thought (IDK know though, but I'd be checking my contract). Are you in a union, it is good to also have that as a backup.
Anyway this is a situation where you've got to take back some power, so spend the weekend doing some plotting and planning here, listen to some empowering music, watch Terminator 2 or whatever you need to do to get yourself psyched into kick arse mode.
As for looking for another job, hmmm normally I'd say hell yeah, but then you won't get maternity leave for 1-2 years
I'm not sure how important that is to you at this point or whether for your emotional health you just need to walk. But I'd be fighting back first. See if you can make this f***er look bad