Might be worth you contacting the school to find out if they have any info.
Other options (which are far from ideal!) include train about 7am Romford to Shenfield Station and bus from there about 7.27am arrives Westcliff 8.15am. If you then moved somewhere near Shenfield Station it is possibly the best option as you have the train to Chelmsford or bus to Westcliff. I also know someone who gets the train (+short bus ride) to Southend Girls from there.
Billericay is another option as you have train or bus options to the Chelmsford or Southend/Westcliff schools. I know a girl who gets the train from Billericay (instead of the bus) changes at Shenfield for Chelmsford. They tell me it's cheaper than the bus.
I do sympathise and best of luck.