DS is 7 and has always had a strained relationship with his dad. Before lockdown in March 2020, DS's dad lived 3 hours away with his parents, which meant that he only saw DS once a month. He very rarely FaceTimed, texted etc. during the times he wasn't with DS, which lead to lots of tears, tantrums and DS not wanting to see his dad. He would also take DS to his parents house for a few days during the holidays.
At the beginning of the year, when lockdown ended, DS's dad moved 40 minutes away and it has meant that he has seen DS every other weekend. He never has him overnight as he lives in shared accommodation, and I let him come into my home and spend time with him here, as it gives him the opportunity to put DS to bed and spend quality time when the weather is bad. It took months for DS to accept seeing his dad every other weekend, and there were often tears, tantrums and DS often said he 'didn't want to see daddy.' More recently, he has got used to the routine and with encouragement from me, a lot of these issues have subsided. DS also has started having emotional support at school, which could or could not be connected to these issues with his dad.
2 weeks ago, DS's mum was diagnosed with Stage 3 cancer. At first they believed it was Stage 4 and she was offered palliative care, but since the CT scan, they've discovered it is Stage 3 and she is going to be having chemotherapy. DS's dad is now saying he cannot commit to a routine of seeing DS and will see DS 'as and when' he is able to, as he is needed 3 hours away to support his parents. He's said he will see DS at the end of this month, which will make it a month since he last saw him, but he says he cannot commit to every other weekend. I've tried to be flexible and suggest he can swap for weekdays, swap for a weekend, but it's got to have some sort of consistency for DS. He is adamant he cannot be consistent and will just let me know as, if and when he can see him. He's also said he is cutting DS's maintenance by a fifth as he needs the extra money to support his parents.
I am trying my best to be sympathetic, understanding and flexible as it's an awful situation for him, the prospect of losing his mum and DS losing his grandmother. At the same time, I am worried about my DS, his self esteem and their relationship. It's really important that DS sees his dad regularly and I know that this is going to set him back once again.
AIBU and what would you do in this scenario?