Whilst I have every sympathy with the OPs situation, I suggest we have to accept that any travel at this time could be subject to last minute changes in regulations and policy.
I have to agree with the comments above that it is always the travellers responsibility to be informed of immigration requirements and government advice, and whilst airlines might try to assist with providing such information to their passengers, the passenger must should also know the relevant government websites to be able verify such information. It is very disappointing that Qatar have seemingly not tried to help their passengers more by proactively those with flights on the first few days of the new restrictions, but as they still struggle to notify passengers consistently of flight time changes, I guess it is par for the course.
I was personally in a similar situation back in Jan 2020 in China when borders started to close and the UK government strongly advised UK citizens to leave China... I had a frustrating day trying to reorganise flights back to the UK and trying to keep checking the route I had booked remained open.
Good luck sorting the return journey, I know how much the UK have been dependant upon NHS staff who come from the Philippines in the past year, I hope this doesn't take the shine off a no doubt well deserved break.