I can sympathise with some of the problems you are experiencing, however I would suggest there are a number of things you can do to address the situation; part time, parental leave (4wks per year), unpaid leave (seasonal), base change to LGW (where you will get some w'ends off), change to long haul after freeze, OR and this is a big one, a move back to the right seat.
As an aside, I assume given your lack of potential movement that you are an ex-bmi employee. If this is the case, I would continue to push for a move onto the main bid list. This is affecting a number of people, who despite having seniority are being held back in order to feather the nest
of those higher up and protect the long term validity of the ex-bmi bubble. Rumours are currently circulating that the size of the bubble will not work under JSS. If this is the case there will inevitably be a push to integrate the two lists with natural seniority. I suggest the next 18mths could see a real positive change for you.