Do I stay or do I go? Relationship advice needed

I will try and keep this as brief as possible. Firstly, a brief background before the problem. I’m 23 and I am with my partner who is 29. We are in a same sex relationship, of which is my actual first long term relationship, and my first relationship with a girl also. Actually this is my first relationship ever. I’ve only ever been on one night stands or had brief flings with guys. We met almost 4 years ago and bought a house together after a year of being together. Relationship was great at the start very loving, sparks flying the usual, and then things started to appear. We’d argue over me being too needy (at the time I was in the military so needed the support) and we’d argue over her going out that sort of thing. I felt for a long tome that I was giving my all and not getting much back however that did change. We grew up and moved in to our house and things were good, we got engaged (she proposed) and here we are almost at our 4 year point. My partner recently gave birth to our month old baby girl through the help of IVF. I am a registered parent on the birth certificate. We had a lot of arguments over the baby situation, just how it would come about, but we were happy once we were set on IVF. It seemed that her one goal in life was to have a child, and being attracted to girls made that hard for her! She’s wanted a baby from the offset of me meeting her. Perhaps we were at different stages of life? Considering the age difference, but I am old before my time. In all honesty, I had no intention when I met her of even having a full on committed relationship, moving in and having a baby with someone. I’d only just realised I maybe liked girls and then all of a sudden it’s gone from 0 - 100 and I have a mortgage and a baby with her. So let me explain why I’m here anyway. So I thought yeh she’s the one, I love her with everything I have, and I want to be with her till I die. But for over a year now (before the pregnancy) I won’t lie, I have been having a lot of doubts. Being tied in with a house and our futures stopped me leaving and I forgot about it and carried on with life. But now a year later (and after the very recent birth of our daughter) I find myself considering a way out again. Here’s my predicament: I love her, a lot. I’d do anything for my partner and I’d struggle to not see her. HOWEVER. I feel like I’m just living with a friend. In all honestly i need to be truthful when I say that I’m getting nothing out of our relationship and I felt like this for a while. There’s nothing there any more. I couldn’t remember the last time we say ‘I love you’. Or the last time we hugged or kissed, or even got intimate for that matter. And the worst part is I don’t even miss it. I almost don’t see her that way anymore. I see her as my best friend, who I love, who I live with. There’s nothing more than a good friendship anymore. I find myself thinking about how much I’d love to have flat to myself and not have to deal with the tie down of a relationship any more. But the question is, do I throw all that away? Do I leave the girl I’ve been with for 4 years, who I have a mortgage and a child with? Do I stay and pretend I’m happy and these feelings don’t exist? How do I leave when we own a house and have a very young baby together? I’m not happy and I don’t have the heart to leave, but I don’t have the strength and patience to stay either. Any advice from anyone?

What if we have tried this? I feel as though nothing is going to change how we are now. But the guilt of being too tied in is stopping me going. Is that right to think that?