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.
It sounds like part of your issues involve poor treatment from others, namely you being there for them when they need somebody, but them not being there for you. Next time somebody "needs you" for something remind them that they were not there for you when you needed them, and that you are sorry, but you can not be there for them at this point in time.
Standing up for yourself is an important part to moving forward.
gentle hugs.
The other time, I called the crisis line at the university I was attending. A friend of mine had committed suicide, and I could not stop crying. I was not in danger of harming myself, but I did have uncontrollable spasms of grief. I was encouraged to call back if I needed to talk longer, and was offered some counseling resources that I already knew about. I received validation for my feelings.
Both of these crisis lines were not specifically for suicide prevention. I have never called a suicide prevention line, but it may well be that they have to limit the time spent on a call where the person does not seem suicidal, in order to serve others who are. Hopefully though, at a minimum they would provide a resource to assist the caller getting through whatever they are dealing with, even if they can't spend time on it themself.
God bless you and keep you.