Sky early termination charges - not sure if my minimum term has ended

I've been with Sky since 2014, but in March 2017 I took up their Sky Fibre offer, at which time I received the following by email:

I'm writing to confirm that you have agreed to take up our fantastic offer of:

• Sky Fibre Unlimited (discounted by £8.99 per month, with remaining duration of 18 months).

We also wanted to remind you that as part of this offer, you've agreed to a new minimum term for the products listed in the table below:

Subscription		New minimum term Start Date	New minimum term commitment
Sky Broadband	07/03/2017					18 Months
Sky TV			07/03/2017					18 Months

So, at first glance I could cancel without early termination charges. However, in September 2018 I changed my TV package. I moved from the old Family TV Pack to the new Sky Entertainment with add-ons, and agreed a couple of small discounts at the time (my haggling skills need improvement, made the mistake of accepting the first offer!).

My question is of course, did I agree to a new minimum term commitment at this time? The email is not completely clear, it mentions minimum terms but nowhere does it give a new start date:

Here's a summary of what has changed on your Sky account.

Your new Sky TV package

• Sky Entertainment £ 25.00
• 18 months In-Contract discount -£ 5.00

£ 20.00

• Sky Kids £ 5.00
• 18 months Sky Kids Subscription Discounted -£ 1.00

£ 4.00

• Sky HD £ 5.00
• Sky Box Sets £ 5.00

Your Sky TV package will be effective immediately unless otherwise agreed.

The following has been removed from your Sky package

• HD Basic

It also says:

Your Multiscreen and/or HD subscription have a minimum term. If you cancel these products during the minimum term, you may incur a charge any additional charges will appear on your bill.

And:

About the length of your contract

A reminder of your contract length

The table below displays the minimum term that applies to each of your new services.

Product	Minimum Term
Sky TV	18 months