I see a lot of good advice here, and I'm going to be late but approach it from a different angle.
If you've spent so much time with your spouse around, and now you're at home alone, and you're working remote, then you are going to need a lot of socialising outside of work, because remote work does not meet the same needs for seeing people in person (I've been there).
Humans are social animals, we need some interactions with others, and you are just getting way too little.
The issue is not 'how to be alone?', it's how to satisfy your social cravings with in-person interaction, once you have that at least some of the time, being alone for the rest of the time is much easier.
Yes, I very much agree. I think it is irresponsible to take antidepressants for something that is clearly an issue of "normal" life scenarios like hearthbreak and loneliness. It is normal, but also very much fixable by gradually putting yourself out there.
Just because OP takes medication after a break up, doesn't mean it's a "normal" life situation for them. They could have suffered from depression before, it's not even clear if they started only after medication. The break up could also bring up some childhood trauma, like the loss of a loved one. What seems to be a normal life situation to someone might not be a normal life situation for someone else. I agree though that if no depression is diagnosed it's a bad idea to take antidepressants.
Yes, that shrink of yours is doing you a disservice giving you meds. Not all negative emotions need to be suppressed with medication. Life has its ups and downs, and drugging yourself out of the bad states will not make the sadness go away, it will only turn you numb to it, making you less empathetic to suffering in general. Instead, what I would do is try to have as much human contact as you can, talk to anyone, with the lady from the grocery store, with the foreign african guy from the elevator. Carry that extra box for the delivery guy that seems to struggle nad is having a hard day. Just experience Life. You will see how similar we are to each other, how we suffer and smile, how we despair and hope. Try to build a network of support around you and don't forget that what people remember about you is how you make them feel. Life is not some multidimentional functions with parameters that needs to be optimized. Life just is. So live it.
During 2020 and 2021, I think many of us were bitterly aware that Zoom calls and online stuff was no real substitute for genuine social interaction. Better than nothing, perhaps, but there is something so much better about being around people physically. (That last bit sounds a bit creepy, but hopefully people know what I mean!)