I would say - still, national carriers for your particular needs. British Airways would be my choice. The 'flag' IATA carriers are the only ones that still retain some semblance of the 'old' form of airline customer service. DO NOT fly low-cost under any circumstances.
Perhaps the best low-stress option would be to take someone else with you, and then they can take a lot of the burden of moving through the jungles of airport check-in and travel through the terminal to the gate.
I do wish you the best of luck - happy landings...