Ditch the OH? Mine wouldn't even consider opening his Big Gob to make such comments …….

and I would be inclined to tell your OH that 'no, health anxiety won't improve because you don't support me or give me condifence!' …….
It would appear that your Mum is 'too old' to take on your problems. I know mine has told me in recent years that she 'doesn't want anyone ill in her house as she can't cope as she did when we were growing up'. That's a fair comment?
Ask your GP to refer you for counselling. Or you could find a MIND group which would give you the chance to discuss the various worries that you have ….. they have been very supportive to me in recent days.
I take BBs to stop the anxiety surges and they have worked since 2002. As well as an emergency tablet for when the anxiety takes over. The AD helps the depression and I vary the dose as necessary with my GPs guidance. Without him and my supportive DH I wouldn't be here ………
Ask your OH if he is afraid of what might happen if you had a serious illness or if he is 'fed up' with your worries? If the latter then don't tell him, as far as I am concerned without support he loses the 'right to know'. Tell him that you will discuss your worries with your GP etc.. I consider that the text is a form of abuse ………. HOW DARE HE!
If he's like this when you are worried 'in case' you have an illness that might need treatment I don't think he would be any more supportive should you have something serious. Time to think about where he is in your relationship. Do you know a good lock-smith?

I know that if Himself even sneezes I go into panic mode but I wouldn't consider sending such a text!