I'm type 2 and I have loads of tattoos. I've had a few done after being diagnosed and none took longer than 5 days to heal. Obviously that is different for everyone, so I'm not sure if any advice would be worth anything.
I use vaseline on my tattoos to help them heal. Also, if I can (depending on the location), I cover them with plastic foil during the day. It makes them 'sweat' which speeds up the healing process.
In the past I've used an ointment containing cod-liver oil which works even better and quicker than vasiline. I used to live in the Netherlands, so I don't know if this is easily available in the UK. You might want to ask your tattoo artist about that.
but the last one i got took ages to heal .and this time its a full arm that am doing has anyone else had one done and do you have any advise in after care