Despite the situation you sound level headed and in control OP- you are doing better than you think and bloody well done you.
Is there something you can go and focus on, a practical activity- even something a bit shit like washing up or tidying a drawer, i always find distraction is the single best way to stop it in it's tracks. If you're lying in bed just get out of it and do some other thing somewhere else, i find it kick starts my brain a bit into moving on to the next thing rather than just staying still cogitating in a pool of anxiety. It's nearly 2am so apologies for the essay and shit grammar but here's everything i have off the top of my head....
You could try something like the Bach Rescue remedy if you haven't, even if it's placebo just taking something 'for' the anxiety can help some people, it does seem to get a lot of praise. I always stick a few drops in my water bottle if i am travelling ( anxious traveller) and it makes me feel a bit better knowing its there - obviously sounds silly but who cares!
I was advised once by a therapist that it can be helpful to snap yourself out so to speak by focusing on the room you're in and just start describing out loud to yourself or in your head, everything you can see in as much detail as possible and keep going.
If shallow breathing is an issue get yourself online and search for an 'anxiety breathing gif' - or get an app- they show you exactly how you should be breathing and following the breaths in and out makes it easier to focus to get the breathing back in order and bring down the feeling of your heart racing. Also if you're feeling claustrophobic open the window a tad and remind yourself you aren't trapped and are in control
It will pass, because they always do don't they in the end. Agree with the others that perhaps speak to your GP about this if it's new, perhaps the dosing needs to be tweaked or you can be offered something such as CBT to help manage the anxiety while you wean off of the meds.
I can really empathise with what you say about it being worse at night, for me i think it was just because there's nothing 'going on' at night, it's all quiet, everyone's asleep. You're much more aware of things. I used to be so bad that every little noise in the house made me leap in fright and i'd end up in tears unable to understand why i felt so bloody unbearably on edge. It was a horrible horrible feeling BUT no harm will come to you, and it will pass.