Tri Girl,
While I’m not married, I am with my partner for 13 years. We have no kids (dunno if you have, don’ think I heard you mention any).
Of course a relationship is not the same it was back when, especially when you got together quite young.

While I have absolutely no clue about you in truth, I get a feeling that the blues you are mentioning is really dragging you down –it’s the middle of winter ... I had a bout of depression for a period in my life and it made me question everything.

Are you sure there isn’t a lot that you appreciate about the current state of your relationship? Is this the right time to beat yourself up?
Maybe you need to get out and catch some fresh air together?
You really might need some help considering the thoughts you are having. I’ve had them and they are not pretty, and they are not worth having.

Why not seek out a counsellor that will see you, and then if you have worked your personal things and you still feel not sure about the relationship, work on that together ...

Thanks for reading and letting me get this off my chest. I don't have family to talk to, and I don't have many friends to talk to. I feel kinda alone...
I understand you really feel like crap, please don’t despair about everything. There's stuff worth holding on to.