I am in the same position with type 2 and asthma and high blood presure. I work in a local co-op/petrol station so social distancing is almost impossible. After my shift last thursday I started to self isolate. Now it looks like I am not going to get paid as no-one in my house has symptoms. From this site I thought this was the advice and I will continue to do the 12 weeks paid or not!
Hi Chrisgreen6, Fromm just comparing what you tell us with what Clarkey tells us, you appear to be at slightly more risk than they are, but again you don't appear to fall into the category requiring shielding, so the advice is just for social distancing.
However if you can afford to do so (and if you employer will keep your job for you) it may well be worth taking extra precautions for a few weeks until after the peak is reached.
From the modelling I have seen the peak for the UK is likely to be in only 2 to 3 weeks, so depending upon how this plays out in your local area you may be a lot safer in only 5 to 6 weeks and so not need to 'self isolate' for a whole 12 weeks.