Received an email from UK Emigration and confused

I have received an email from UK immigration. would you kindly inform me what does mean? i am so scared. Because, my travel planing is 27 of The current month. Please suggest me by reading below texts. Thanks in Advance

Thank you for your visa/entry clearance application which has been received and is under consideration.  We aim to process non settlement applications within 15 working days and settlement applications within 60 working days (unless you have opted for a Priority Visa service).

We are unable to resolve your application within these customer service targets, as the processing of your application has not been straightforward. Please be assured that we will continue to progress your application to enable a decision to be made as soon as possible.

Please do not attend the application centre until you have been contacted by the VAC.

Kind regards
Croydon DMC

This is an automated message - do not respond to this email address as incoming mail is not answered.  If you have a query regarding your application, UKVI contact details can be found at www.gov.uk/contact-ukvi-outside-uk

This email is intended for the addressee(s) only.  All messages sent and received by the Foreign & Commonwealth Office may be monitored in line with relevant UK legislation
available at https://www.gov.uk/government/organisations/foreign-commonwealth-office/about/personal-information-charter