I feel tired. Exhausted. Not wanting to kill myself, but just don't want to exist for a period of time.

My depression comes in cycles, mostly in winter, and when I start to withdraw, usually in the form of being on my computer, I sink. This same pattern has ruined a few relationships now. The heartbreak is terrible and my last S/O and I tried to make it work again but this time, after she initially broke up with me, I pushed her away because I felt like another cycles was coming. Now she's blocked me completely, it hurts, but I understand either way. I am trying to maintain hope, but I'm 37 now and I feel like that hope is fading.