Missed Eurostar Paris to London due to SNCF cancellation

I am travelling on a global pass one month first class fare between England (origin) France and Spain. 

I am travelling home from south of Barcelona to Newcastle, UK. I am travelling with an assistance dog which make things a little more complicated. I travelled from Barcelona Sants to Latour du Carol on the 14.30 train on Friday 21st April. I had also booked onwards travel to Paris on the night train from Latour du Carol (Pyrénées) to Paris, Fri 21st April, dep. 18.49 arriving 22nd April 06.33. My Eurostar was booked for Paris-London on Sat 22nd at 09.13. 

At 18.00 SNCF cancelled the night train and I was stranded in Latour du Carol. The staff at Latour were inexperienced and unhelpful and told me to head back to the next town (Puigcerda, 4 mins away by train, but in Spain) and stay the night, getting the train in the morning back to Latour de Carol. This was a bad idea as I arrived in puigcerda and there were no trains in the morning and no one to help. I got a cab back to Latour (€40), found the only hotel I could who'd take a dog (€108), got a lift to the station in the morning and am now on a very convoluted, long journey to Paris, via Toulouse and Bordeaux. I arrive in Paris at 8.pm to Montparnasse. The last Eurostar leaves form Gare du Nord at 8.13 and with an assistance dog, I cannot get a Eurostar train to London from Paris later than 18.30 as they need someone in London to check the dog's pet passport etc. So. It looks like I'll be stranded in Paris tonight. SNCF have told me that as I didn't book the Eurostar in the same ticket or the same time as my SNCF ticket they are not obliged to put me up in Paris, nor cover any onward travel.

There are no Interail pass fares left on Eurostar trains from Paris to London until Monday. The Eurostar office is closed over the wknd so I cannot ask anyone by phone. The TGV train I'm now on, from Bordeaux to Paris now gets in too late (35 mins late arriving at 8.pm to Montparnasse) to find anyone from Eurostar in person at gare du Nord (last train leaves at 20.13pm).

I need to get back to London tomorrow (which will already be a day late) Does anyone know: 

a) whether SNCF are obliged to put me up in Paris tonight and

b) what is the status of my Eurostar ticket (originally 9.13 today, missed due to French strikes and cancellations).

Are Eurostar obliged to put me, and my assistance dog on the next train (Sunday morning). There are spaces but not pass fares..

Thank you SO much for anyone who might be able to advise on what to do, or what my rights are. 

Cheers 🐾