how do you know when enough is enough?

i’ve been wondering that a lot lately.  how do i know when enough is enough?  how do i know when it’s okay to give up?  i’m 28…  i guess even as a kid i felt weird.  i had constant thoughts of death.. was plagued by nightmares.  now looking back i had anxiety and ocd.. i would constantly tap.  i was quiet.  i got picked on for being overweight from primary school until high school.  at 14 i realised i was a lesbian.  i told a few ‘friends’ and everyone knew by the end of the same day.. i withdrew completely.. i became depressed.  i considered whether someone asked me a question or a statement.. q’s required a short reply.. statements required no answer… i was like that for 4 years.  my dad was constantly on my case about breaking my mum’s heart etc.  it’s the first time i felt suicidal.  after high school.. my friend and i began to go out clubbing…  it felt okay for once…  i was surrounded by other gay people.  i started drinking and clubbing a lot..  i quit uni.. i hated going by myself.. i didn’t want to make friends..  i started dating a girl.. we are still together.. we knew each other in school..  we’ve been together for 10 years this year…  i love her and our chihuahua more than anything.  i live for them…   i have been diagnosed with severe anxiety and ocd.  i guess depression too…  as i have been suicidal for half of my life.  this time last week i was sure i was going to be dead by the end of the weekend.  i felt ready…  i was okay about leaving my gf and chihuahua.. i couldn’t see any other solution..  we are experiencing financial difficulty..  my gf can’t work cause she has a back disease.. and i only work part time where my mum works as i am very anti social.  so i feel like a let down.  i have so many rules for myself.. i can’t show emotions.. i can’t ask for or want stuff..  i’ve always been like this..  i am on so much medication…  i feel like a zombie… i have began to decline it.  my psych and counsellor know i cut etc…  my counsellor was so worried that she has come to my house.. and she has called me…  i’m struggling each day.. i don’t believe that suicidal is selfish.. why would people want their loved ones to live each day in pain…  we’re already dead inside…  just let us go…  i’m not sure how long i can hold on for.  it crosses my mind every day..  i look at my gf and my chihuahua right now.. and i love them…  but they might be better off without me…  so how do i know when it’s okay to give up?