You absolutely can achieve the results you want on your own much in the same way you can achieve the physical results you want in the gym without a personal trainer.
A personal trainer certainly helps get you started especially if you don’t know where to start, and gives you the work you need to be doing outside your sessions to meet your goals. A good therapist is the same way, go in knowing what issues you are trying to solve, do a shit load of work outside of your sessions, talk about progress/setbacks to stay on task. Improve to the point you no longer need a trainer.
Starting is often the hardest part for lots of people, but it is worth starting. I recommend anything that makes starting less overwhelming.
Depression is a real motherfucker. For me it was like being in a deep hole, and the worst part was there was a ladder in the hole with me. All I had to do was start climbing and eventually I would get out. Every day for awhile was “the hole isn’t the end of the world, I’ll start climbing tomorrow”, then tomorrow would come and I’d feel worse for not starting. Therapy isn’t magic, but it’s starting the climb. Stack up all the wins you can imo.