I completely understand you have questions about how the current measurements will influence your travel plans for next week, and I'd love to point you in the right direction.
The Irish Authorities are currently advising against all non-essential travel overseas until further notice, and this includes travel by ferry. The Irish Government's next review of the current regulations is due to take place around July 9th, after you're planning on travelling, and you can keep an eye on the official news updates and resources on this page
Public health advice for people arriving from overseas is to self-isolate for 14 days. You do not need to remain in the country for those 14 days, but you should follow the self-isolation guidelines
for the time that you will be in Ireland.
Your ferry company should also be able to tell you more about your journey. Have you been in touch with them yet by any chance?
Check out the Traveller Health page
for more helpful information and resources as well.
I wish you the best of luck, and stay safe!