Depression Support Group
Depression is a real and debilitating condition that is often misunderstood by family and friends. Its meaning can range from a prolonged period of sadness to an actual mental illness with specific symptoms. Find and share experiences with others who are going through the same struggles.

You say you feel like you want to do something better. Are you able to volunteer somewhere nesr to you for example in a soup kitchen, charity shop (thrift store). Do you like working with elderly, adults or children? May be worth looking into seeing which volunteer work would suit you best to give you that sense of purpose.
I definitely suggest volunteering, as @Polkafly said. Any of those places are great options to get involved with. Also if you're a member of a church then they probably have ministries where you can invest yourself in others. A church may also help you find some of that purpose you're seeking.
God bless