14year old boy teenage issues

Hi, I am a parent of 2 boys (10&14 year olds). I was diagnosed with a liver cancer in September 2019. My husband (the boys father), passed away in a motor accident 7.5years ago. And I’ve repartnered in the last few years. My partner has been living with us for about 2.5years. I am noticing increasingly that my boys, particularly the 14 year old is showing more dissrespect towards me. And even more noticeably when he has been around my family (mum& sisters). I still look and feel well so I can understand that from what my boys see, I haven’t changed. So in their minds, they must be thinking, how can I be so sick if they can’t see it?? I understand teenagers come with there own issues, but I feel like I’m at wits end.

I have reached out to CANTEEN for some counselling for him.

Any other suggestions of what I can try? He’s not much of a talker, so I’m struggling to get much out of him!