My girlfriend doesn't always want me around ,,,


My girlfriend doesn't always want me around and her 'ex' is constantly staying at her house.

Hi beautiful people, the reason I'm writing is that I believe my girlfriend only wants me around when it suits her and is constantly telling me when I can and how long I can stay with her (I normally come up on weekends). I'm wondering if she does love me, she recently went for a month trip to New York and she admitted to hardly even missing me while she was gone, she was constantly on my mind and I couldn't wait to see her. When she arrived home she wasn't that emotional. The other dilemma is her 'ex' is constantly staying at her house and travels nearly 2 hrs each way nearly every day to stay at her place when he has his own place only 40 min away. I feel a degree of non-acceptance on his part when I go there on the weekends. My girlfriend is about to go on holidays and I suggested that we could hang out locally and take advantage of some of that time as I'm currently 'in between jobs', the 1st thing she said was that she would be busy and had to do some family things and she couldn't commit to that time but we would do something 'nice' now is the last day of work for her and her holidays will start and now I have a cold and she's told me she doesn't want me around because she may get sick, yet her 'ex' was sick recently for 2 weeks and stayed at her place and that wasn't a problem. Please help I feel unwanted, not valued and not loved even though she constantly tells me this. I feel her dog may have more value than me!!
Regards C