You've recognized you need help. It'll be hard but you've already taken the hardest step.
A quick bandaid that you can try right now is meditation. My favorite meditation app is Headspace. You don't even need a meditation app but when you start to feel overwhelmed start breathing in and out. Focus on your breath. If you have the energy, take a walk.
If you have a lot of energy, hit the treadmill or run for 40 minutes. If you're a runner great, do a 5k. If you're not a runner start the c25k program. Getting your body moving helps. It might be the best, most natural help you can get. When you push your body, and your body feels heavy, your arms feel heavy, and you just want to literally stop, lie down and kiss the ground, if you keep going through all of that, you will build mental strength and also experience dopamine from a runner's high. Nothing makes me feel better than a run, even sex.
If your depression gets worse you might not have the energy anymore. I would highly recommend you recruit the help of your family and friends so they can support you in case you get worse. I wish I had someone that could have helped me find a therapist or psychiatrist while I was struggling. It was so easy but so overwhelming. If you need help looking for a provider in your area, I can help look up options for you. Also here if you ever need to talk.
If you see a psychiatrist and they prescribe you drugs and they work, then that's awesome. You might just need one drug that could lift your mood just to get out of this slump right now- so it's definitely worth looking into. Forget the stigma, if it works, you'll wish you had done this a lot sooner and you'll recover a lot faster too. Are you getting enough sunshine, vitamin D, and B?
This might be shitty advice but something that has helped me a lot is putting things into perspective. If you lose your job, you could find another one. If you start having financial trouble, maybe you can lower your expenses. Maybe identify your worst case scenarios and possible solutions to that and see if it would be that bad and life destroying. It sounds like you've had a really shitty couple of events and of course that would get anyone depressed, so please don't take anything personally, and focus on your health, happiness, and recovery.
For me when I was struggling, the worst case scenario was that I could just pack up my bags, move back home, and start again. That didn't seem so bad. I still had my health, my skills, my relationships, and I could find another job. These days whenever I feel sad, I just think about all the things that I do have that lots of people don't. I'm alive which means I still have the ability to change things. Life can feel shitty but it's still a blessing and a privilege if you were born with the right things and if you're a software dev, you were. You can literally do anything you want, you're just currently in a slump, this slump doesn't define you. Wish you the best of luck.