Oh...been there/done that, Jonny! I actually joined Psychcentral after a major heartbreak, several years ago. Like you, I had tried some therapy, and felt much as you did, that it was fruitless and the counselors didn't really care...but, hey, they were doing their jobs to try and see WHY I was so fixated on one person and SO obsessed. I didn't want to hear! In the therapy defense, they have to take time to set the groundwork, and only those dedicated to it can reach improvment. Instead, I just wallowed in my grief for an inordinately long, long time, putting one feeble step in front of the other, then taking two steps back, moving around like a zombie, thinking I would see him on campus where I was working on my M.A. etc, etc.
I suspect you are rather young. Don't take offense when people tell you that you will get over this. You will, but maybe it will take a long time. The amount of time is up to you. You can allow yourself to grieve as long as you feel the need. Be kind to yourself!
There are relationships I still look back upon, and from which ....at the time...I thought my life was over. It was NOT! And those were very traumatic at the time, some impacting my lifelong decisions, some of which were wrong ones. In retrospect, I see that all the bad hurts made me who I am, a mature woman with insight and compassion. Being alone for while is not the worst thing to happen. This can be a time for personal development and true growth.
Patty