Please help me

My girlfriend and I have been dating for three months now and she told me from the beginning that she suffers from ADHD. She does not currently take any medications or seek any counseling/therapy. The biggest issue is she blames all of her shortcomings on ADHD, which I don't disagree with but it seems to be hurting our once amazing relationship. I am hoping that by stating our issues on here someone may be able to chime in with similar stories or advice that may help. 

 

1. She tells me she wants to see me on X day. X day passes by before she finally says let's meet, but within an hour is ready for bed before we can even spend some US time. It almost feels like she just doesn't care to spend time with me or just forgets about me.

2. We are already having arguments, however it's always directed at me even when I try to chime in I am told I am wrong and that basically leaves me with the assumption that my opinion doesn't matter.

3. She says she is listening to my wants (mainly wanting to spend more time with her so that we can grow as a couple) and trying to make the effort, yet referring to #1 and the efforts put for it seems like there is lack of.

4. The sex life...well what sex life? We've had sex 3 times in 3 months. At first it didn't bother me, I really care for her and wanted to do everything to make her happy, but it seems she doesn't even seem interested in me sexually. I know she had a pretty sexual life previous to me, I just don't know what to do and I've tried talking to her about it.

There's many more and more details, but I am kind of new to this whole reaching out and trying to find advice. I really want her and I to work, she is a great woman and I care for her very much.