Changing the way you think is part of getting better. If you hide behind the reasoning that depression has absolute control, then it's like refusing to take medication for an illness.
You can take all the medication you want for a broken leg, but you still have to exercise it once the cast comes off.
Mental illness can be temporary. Some people will have a "spat" of illness, they'll receive treatment like a broken leg, and then will need to overcome and get back up then never have issue again. Unlike a broken leg, chronic mental illness is more like cancer or asthma. A chronic condition that doesn't heal on a set time frame. You can't simply not use your mind like you can a leg while it mends, and in life long illness the mind can try to "break itself" at any moment. It requires a lifetime of vigilant monitoring, care, and possibly medication. It can go into remission for even decades then suddenly return. It can rob you of moments of joy or even kill you. Like any disease you should get professional help to fight it. You should know it isn't your fault. Your mind state and actions can aggravate or alleviate some risk and symptoms, but no one can 100% control their body or mind. You aren't a powerless victim and you are the most important part of your own recovery.
As an autistic I say one of the best things people did for me was just try to be there when I need it. Not smothering me but still in arms reach if I need them.
You can take all the medication you want for a broken leg, but you still have to exercise it once the cast comes off.