Good morning @Former-Member and thanks for stopping by ... and mostly thanks for sharing 
I definitely want to expand on what you've said ... let's talk about the topic of medication first.
Medication is a definite TOOL in your toolbox! Sometimes due to hormal imbalances, diet, trauma, genetics ... the list goes on ... medication is a great addition to other practices (tools) we have available to us.
So, if you would allow me - it's not sad ... it's necessary at the moment, and you've qualified that by saying maybe it's temporary. Maybe it is, maybe it's not as temporary as you think.
This leads us to the second part you shared and that's the drive to work and all that thinking and catastrophising you're doing! AAArrrgh you poor thing! It must be awful for you ... yet you (and so many of us) do it so well, not leaving one mental stone unturned until we've thought of every possible thing that could go wrong until our mind is a complete mess and ... hey look you're at work! 
Firstly, hands up who does this? Yes, we all do to some extent. It's human nature to do this with our minds it's called ruminating and all us deep thinkers out there are very good at it ... unfortunately it serves NO purpose ... no ... sadly no purpose at all. Ruminating is what brings many of my clients to my door - they can't stop the mind racing away from them with all kinds of catastrophic, dramatic, future seeing, black and white thinking thoughts!
Acutally they're known as automatic thoughts ... they're well known to the mental health industry. The idea around them is that they are our mind's 'go to' when we're anxious ... they automatically pop up!
These negative automatic thoughts or NATs as i call them, can be our worst enemies. And like all enemies you need to know them very well or they just might get the better of you.
So, for those of us who have NATs one thing to definitely have in your toolbox is a strategy for dealing with your NATs ...
For example ... if I may use your example @Former-Member your 'go-to's' are fairy catastrophic and dramatic, you imagine the worst .. i believe you also favour projecting into the future - in those moments you like to be a fortune teller! Predicting the (not pleasant) future ... all the while increasing your anxiety levels to the point where they're causing you harm.
My strategy is to RECED away from these thoughts ... yes it's another acronym
R - Rewind - ask yourself, "hey what was I just doing or thinking that led to this catastrophic thought about work?" When you look back you can easily see what led you to having your NAT (this makes it less powerful)
E - Explain - tell yourself "it's not real it's just a NAT" Talk to yourself ... it's not real I'm just having a thought right now. And you can be sure it's a NAT if you're just thinking it (unless you just remembered you left the iron on then it's time to turn back hehe)
C - Clasify it - go ahead and call it - "oh I'm having a NAT - a catastrophic/dramatic/fortune-telling/black & white thinking .. thought. (choose one) Oops 
E - Evidende - now find evidence it's okay to let that NAT go ... this requires self talk and self understanding, What can you see/hear/smell or touch that tells you it's just a pesky NAT getting in the way of a perfectly good drive to work on this find morning ...
Now, what do you think? Can you learn to RECED away from NATs?
It's very helpful when you're deep in one to simply stop and SEE yourself having the NAT ... consciousness is a great thing.
MIndfulness is very powerful for that reason - when you're in the here and now your mind is protected (somewhat) from NATs ..
Toolbox contents: Medication, RECED instructions and mindfulness. Looking good!
Again many thanks for sharing @Former-Member 