While it definitely isn't necessary to have a "significant other" to feel happy, humans are programmed for that connection. Healing from trauma and depression is a long, hard road. Please, please revisit your commitment to therapy. Find someone different. One suggestion I would make is to try to find a certified yoga therapist. This is someone who is a regular therapist (psychologist, social worker, mental health counselor) who is also a certified yoga instructor and has had lengthy training in using yoga to heal trauma. It is an amazing modality and I have seen it work with more than one person.
I also second the idea to volunteer. There's research that shows when we give to others, it actually changes the chemical composition of our brain functioning, which relates to depression.
Let us know how you are doing or shoot me a PM if you need more info.
Disclosure: yes, I am a counseling intern...