Dependency on tablet/iPad

Hi all, hoping for some advice,

Our 6 year old son who is autistic and has a global learning delay regularly uses his tablet. It started as something to engage him while we were together trying to have dinner at the table for example and also in the hope we could use it as a learning tool (so yes possibly our fault we have an issue now!).

More recently we think he turns to the tablet as his comfort/security, if things are getting too much, but we're at the stage now where he has difficulty in doing anything other than using the tablet. We can go for walks and do other activities but he finds this particular transition (coming off the tablet) very hard. And this week just trying to get him to school (he is in mainstream with 121 EHCP support) has caused meltdowns as he can't leave the tablet (something that isn't normally an issue for him). There may be something else underlying making it extra hard which we haven't figured out yet (tired, over stimulated potentially) but does anyone have any experience or advice in this area on how we can make things better for him?

Regards S