Install keeps queueing itself

Install is very slow, but admittedly my internet is very poor. Regardless I downloaded far cry 4 1gb updates no problem earlier in the week. Halo 5 is installing very slowly and keeps queuing itself, effectively stopping the 9gb update and installation. Every so often it will come up with ‘installation stopped’, but most of the time just queues itself.
Anybody else having issue? I’ve cold booted twice, reluctant to erase installation and start again in case it doesn’t work.