Alright, that's an awful thing and I totally understand you at this point.
There was a point, no so far ago, of my relationship where I stood almost one week without making sex with my girlfriend. It probably doesn't compare to your case in a matter of time, but I learned something from it. In a talk with my girlfriend, we reached this point. She told me some things that I didn't really get and then I asked her some good quality questions. Long story short, whenever she felt that I was more interested in SEX than in HER, her legs would close. Honestly, I never thought about that before she told me, it never passed in my head before.
So it comes in three things for you to think about and fix your relationship (even if fixing means breaking it):
1)
If she feels that sex is something that you are taking from her, she won't feel like doing it with you.
I would love to explain this topic further, but even I didn't understand it to the point of being really able to explain to someone. I think it is something that you just feel, and she surely feels it too. Of course you love her, of course you want to **** her hard, but the thing is to keep the balance. Be interested in your girl, ask her about her day, cuddle sometimes. Women are emotional beings, they go from wild sex to cute cuddling in a minute. Just sail in the sea of her emotions, don't try to turn it into a pool. Flow with it. Be true with your feelings, and associate these desires with her. I want to have sex with you, not just have sex. That's the idea.
2)
If she's not feeling loved and understood, her legs will close
It doesn't depend on the base of your relationship, for example, in mine we make sex at least 3 times a week, but usually almost everyday unless something happens (first days of period, we can't meet, etc). Let's suppose that sex isn't happening, and the same time you can feel that she isn't that excited about being with you. Your man radar will start to beep, you know that there's something wrong.
Instead of doing something stupid like going to your man cave trying to guess what's wrong, go talk to her. Sit down, get her close to you (I usually put my girlfriend on my lap, subconsciously asserting some dominance, loving and caring) and then ask her about how is the relationship going, tell her that you felt her distant lately, and add any other details that you find relevant, ask her what's going on.
If you don't have the balls to do that (because you can't make a direct approach), you're gonna play "
Rate Me" game. It's the same pattern, you two sit together, you ask her to rate you and say the things she liked and disliked about the relationship lately. You will do the same to her. As she expose the problems (there will be problems, make sure to keep on asking until she open up), don't take it personally. Even if it offends you deeply to the core, try to learn something from it. If you were doing things right, she wouldn't be feeling this way, neither would you, so take your chance. If you don't really get something that she said, propose a situation, ask her once more, repeat what she said and confirm if that's what she really meant by saying that. Don't be lazy. Also, expose the things you felt, I think it's needless to say that you won't be whining, begging or anything like that. Communicate "you did this, you acted like this and I didn't like it". Be assertive.
Also, listen and do your best to understand her point. I'm not telling you to accept, I'm telling you to understand. When she's speaking, the only things you will say are
"Tell me more, honey",
"So I did this, this and that and you felt this way?",
"So you felt this way?",
"What do you mean?",
"How did you feel about that?". Religiously repeat some of the things she said to confirm, especially if you think you didn't get it right. If you feel that you got everything, you repeat themain points of what she said and then ask her
"Did I miss something? Do you think I got your point?".
3)
Is this the kind of relationship you want?
As you said before, you'd have sex a few times in the month before, now it's 0. Are you the kind of guy that is okay to have little sex with your woman? If so, then you might be okay keeping the relationship. If you're like most guys, you probably won't be feeling good enough by having it a few times a week, because it's gonna make you feel like you're not living to your full potential, that you can have more, that you can do more. Well, if that's so, your relationship needs an even deeper change.
Analize these points and think about it with yourself. You must man up and communicate your boundaries and needs in a effective way.
It is not okay to have a sexless relationship.
It is not okay to be disrespected.
It is not okay to have problems and not communicate. Remember, communication is the key to avoid drama. If you don't communicate, or have a poor communicating girlfriend, you are going to have a hard time. Use the "Rate Me" game as a window to say that, something along the lines
"Honestly, I feel like our relationship is going sexless and that's not something that I want. I don't want to be in a sexless relationship".
Or am I better off splitting now, while she still has a chance to have kids with someone else/on her own? << This is a big issue for me. I don't want to **** her over. She is still very important to me.
That's nice of you, but it shouldn't be your concern right now. You both are in a relationship to have your needs met. If you feel that there's something missing, you communicate. Some guys can do that in a non verbal way, others feel like doing it in a verbal way. If you can do both of them, great. You'll be a good communicator and a man of action.
Keep in mind that in relationships, you either grow together or grow apart. If your needs aren't being met, you talk to her about that and if she isn't willing to put an effort in the relationship, then there's no why being together. You must always pursue your happiness, being fulfilled in your job and have a great relationship. If she can only give you a sexless half-ass one, it's better for you to go after something better.