In law Drama

So I am starting to try and validate my feelings as an infertile instead of swallowing them and saying thats infertility talking. I know if my circumstances were different and my DH and I had been able to have children on our own 2 years ago when we started trying I may not be as hurt or sensative. But Im not and it didnt and this is who i am now. Take it or leave it. And I need to start taking care of me and relizing it is okay to have these feelings.
Since my SIL got pregnant last year she hasnt called or texted to say hi or see how my life is. She only calls when she needs to use my pool or for babysitting. And i just think it is so thoughtless when you dont try and have some sort of relationship with me on a regular basis to call for a babysitter. Dont get me wrong i love my nephews and i love to spend time with them, but it is hard to have a baby over and get up in the night with him when all ill be thinking about is i should be doing this with mine but i cant. And she had a miscairrage so i dont understand why she doesnt get it.
But now she has 2 beautiful children and forgot how that felt i guess. So she didnt even call me after the d&c to see how i was but she texts me last night to ask me to babysit for her on her birthday party overnight, and says "i do want you there just thought you could take him home with you and keep him over night" Obviously you could care less if im there. I am just a babysitter to you because thats the only reason you get in touch with me. It is hard to be around babies. But i love my family and friends, It is a lot harder when thats all your wanted for. SO INSENSATIVE!!!