I love my gf but our sex life is dull

I need advice...So I have been with my gf for about 4 years officially. We were long distance and things were hard but now that I moved out with her (the past 7 months) while most things are going great or ok. Our sex life is dull or non-existent.

I have a high sex drive and I can confidently say my gf does not at all. There is sex happening once a month if I'm lucky and It's dull, feels forced, and has killed the whole romance between us. I do not know if it was always like that, in the past we were more active and she was initiating more but I do not know if she was doing it for me or because she felt that way.

We have had several convos about this problem, every time it ends with the same exact words "I know, I will try more", after this, sex might be more regular for a few times and then goes back to the normal dull thing. There is no passion no more, to the point that I myself do not bother initiating, I touch less and I genuinely feel more irritated around her for smaller things that usually would not frustrate me.

Personally, I do not want a relationship without passion, eroticism or sex. I can see that it does not make me happy and it will also result on her being less happy too. Since we probably feel like roommates other than a couple.

I do not know what to do, I'm frustrated sexually, and also mentally with all that. I feel unwanted and uncomfortable.

What do I do? I do not thing talking to her about it AGAIN will result in anything. I would appreciate some advice here....

Thanks!