Partner (30m) seems to only be in it for the good healthy days, not the sickness or messy days and I’m fed up

Partner of 1.5 years is inconsistent when it comes to care and emotionally availability especially during emergencies or urgent matters. Last year I was sick at the ER due to morning after pill gone wrong. I asked him to bring food, sweater, etc. he said the doctors were taking care of me, he was tired and decided to go home because he couldn’t do anything for me. I expressed to him afterwards how his words and actions made me feel. It was no use because he said he also had needs and was tired from work. A few months after he micro cheated on me during a a family trip. He danced with girls and broke his neck looking at them evidenced on video from his family. I was sick with severe nausea and headache during his trip and he said he couldn’t do anything, didn’t call me, and said there’s nothing he could do. I left him. After that he said he wants to start fresh and he finally agrees that my hurt is reasonable and validating. He said he’d work on his empathy. I took him back but I clarified that I only felt safe taking him back after he went to therapy (he is dismissive avoidant attached) 1 month later one of the babies at a school I work that got me sick with the flu (nothing bad) but my partner brought me a care basket with a blanket, tissues, snacks and meds. I thought maybe he is changing. Fast forward to 2 months later, I took him to Mexico for his birthday. On the first night i got emotional because I missed my estranged sister and her newborn (also her bday). He asked what was going on so I explained myself. He said to stop crying because there was nothing he can do and completely shut me out. I immediately stopped crying and held back the tears because I knew I’d feel worse if I kept crying with him shutting me out. That same night I was severely sick from migraine that caused me nausea. I could not move from fetal position. I woke my partner up for help only for him to tell me to just sleep it off. He turned his back and continued sleeping. 1 hour later I managed to get out of bed and went to the bathroom. I vomited for a while and found the strength to walk to get water and back to my bed. I remember laying in bed for hours without being able to sleep. It was the worst migraine of my life. The next day I spoke to my partner about what happened. He said he was asleep and was tired and didn’t think i needed help. He was sorry he couldn’t help. I was furious. Other examples of this was when I lost my job, family loss and needed some financial or emotional support and I received nothing until after I begged for a while and convinced him to see my pain. Now, other than those lows/sick days, he gave me all the attention and date nights any other couple normally has. He was very attentive on the good days. The good days were really good days. But when shit hit the fan, he was no where in sight. The bad days almost make all the good days not worth it, although the good happy healthy days were the majority. I supported him on his low/sick days no questions asked. Just unconditional love and support. In the 6 months after expressing that he needed therapy and possibly couples therapy, he only went to 2 sessions saying he has no more talking points and rejected couples therapy saying we don’t need it. Why are men like this? How can I avoid this in the future with another partner? I know this isn’t what I deserve. What are your experiences?

TLDR: partner is emotionally unavailable and thinks I need to wait until he heals to be the man I deserve. I’m fed up after 1.5 years.