@Dinosaurmermaid I'm worried about you - because I see a lot of what you're saying in myself. I understand that you've spoken to the doctor, but please try again.
There are SO MANY factors that can make you depressed and just talking things through can help - maybe see a counsellor or try Samaritans either. I'm so sorry that you feel so desperate - but you sound like you have a loving family - so please think of them before you do anything rash.
I have a close friend who committed suicide (in the past I've thought about it SO MANY times but every time something - usually my children, once a tentative friend who still has no idea how close I was that day until I spoke to her) ... but I know the devastation that it leaves behind. If only my friend had spoken up.
I'm no counsellor, but I do have a lot of experience with therapies and desperate situations I've been in in the past and if I can help I will, but please don't go it alone.
A mild anti-depressant might be useful. I rallied against any medication, but actually using anti-depressants for a couple of years, actually really helped my mental state.
Most of all take joy in the smallest of things. Life is truly precious and things really can turn around.
Take care of yourself xx