It sounds to me like something happened and your BF and GF realized their marriage was in jeopardy. They told you that they would need some time to work on it. (Or so it would seem to them as they say that they "warned you".) So, if that is the case you are left with two choices, 1) accept that they need to do this and respect their time with each other, 2) let them know that you cannot accept this if it means that you get no time or whatever it is that you need and ask to separate your lives in a way that leaves you feeling valued. . . .close friend and room mate, but not babysitter or once a month babysitter whilst you get on your feet.
You are much younger than your BF and somewhat younger than his wife. How is it that you ended up in this relationship and living with them? How long have you been living with them? How long have they been neglecting you?