I suffer with depression, and have suffered practically all my life. Even as a child. I had a very difficult upbringing without proper support and guidence.
I liken it to a waterbutt - the sort of large barrel in gardens you put below guttering to catch the water. It may take a while for it to fill up, but once full, it doesn't take much to set it overflowing. It needs to be drained off periodically, else the water becomes stagnant and bad. Likewise, bottling up the many cares and strains of life can leave little room for much else, and then the slightest upset can set you off, lashing out at those around.
For around 10 months, I've been visiting a psychotherapist for is listening to the various bad episodes of my life, allowing me to cry, get angry, expose all the various feelings that have gotten stuck over the years, unravelling the knot of emotions and helping me to understand them, and finally, let them go.
The feelings of anger, abandonement and guilt coupled with a feeling of wanting to hide away and not get involved with life and still quite strong, but getting better. I don't fly off the handle quite so much now or have the feeling that I just can't cope.
I lost my mum when I was 17 and realise that in some ways I wasn't able to grieve. My father and I fought all the time and without support, I just 'got on with it', pushing my feelings down, unmanaged.
For me, depression has been a huge part of my life, but I'm hoping that with the help from my counsellor, it wont be a huge part of my future. If you're struggling with the loss of your mum, then don't leave it like I did. Seek help, talk to your doctor, get some help. I thought I'd never find any relief, but I'm surprised at how (relatively) easy it can be. When you're in a dark, lonely place full of despair, it's hard to see the light at the end of the tunnel, but it is there.