Depression is a mental disorder caused by chemical imbalances in our brains. It manifests differently in every person who has it; eating too much or not enough, sleeping too much or not enough, isolation from the world, and loss of interest in things that once brought happiness among others. People who have experienced trauma or abuse are more likely to develop depression, but people who have otherwise perfect lives can also get it.
The thing a lot of people who don't have mental illnesses don't understand is that you can't really 'overcome' them. You can lessen the symptoms and try to live as normally as possible in a variety of ways, but for right now there is not any way to cure depression or any other mental illness 100% for good.
Medications and therapy should be the first go-tos for help with any mental illness. But in the event they are not readily available to you for any number of reasons there are more home remedy-like ways to help as well.
Getting adequate exercise and hydration as well as a good diet are great ways to start. If you're smoking, drinking, or abusing drugs get help to stop doing so because they will only make depression worse even if they temporarily make it feel better. Finding things you enjoy and doing them, even if it means swapping them around every now and again, can also help.
Having a positive mental attitude can help, but it won't fix everything. And just like we wouldn't tell someone with a broken spine in a wheelchair that their chair is just a crutch and not a necessity for them to live we shouldn't be telling people with mental illnesses that they don't need their medications or that the meds are just a crutch. If you feel like you have depression do what you can to see a therapist and get diagnosed and medicated, that's the best first step to overcoming it.