So I've had rough 5 years trying to have a relationship with my sister and father. My parents went through very messy divorce and it kinda fucked us all up. 

My dad used to being up the past a lot which used to negatively impact me and talk about things that would upset me. He had spent a lot of his time working exhausting jobs chasing that money which all meant nothing in the end as my mother took half of everything. He had no life because work always came first. 

So I distanced myself from him and my sister as I felt that they negatively impacting my life. I have told them few years back that I do in fact have BPD and would be advisable to learn more about my condition by googling and all that good stuff. They didn't do this. The distance kinda grow even wider to the point that stopped talking to them completely. 

My father called to the house few weeks ago but I told my gf I didn't want  talk to him . He give her a  note because basically read "I got stage 3 cancer "

I got really upset and intense emotions took over me. I immediately went to go see him at my family home and he explained the situation. 

Here's the issue, anytime I say something I feel like he isn't listening? I know sounds super silly but I feel as I say something he will say something that no where connected to what I am saying. It feels that he doesn't listen or even try to care about what I am saying. Sometimes I talk about things that he doesn't understand and I'm waiting for him to ask a follow up question but just talks about something else that has no connection to the topic. It's exhausting and being ignored is one my major triggers.  It makes me fully shut down my emotions to prevent a freak out. 

The last time visited him he just rambled for like 1 hour and half  straight and kinda just got up to leave. He drove me and my gf  home and on way home he started asking us questions about our lifes'. (5 mins of real conversation)

I understand that he has cancer but what's the point in inputting to any conversation if I know I'm not being listened to? 

Any advice at all would be helpful and thank you for taking the time to read this.