letting cats out on harness now one is constantly miawing at door!?

ive got 4 cats Spice (17 years) Felix (4 years) Dodger (2 years) and Splodge (2 years)

ive let them out 2 days in a row and left today it had been going well

Now im not so sure, as Felix is constantly miawing ive had such a busy hectic day today, and ive had a splitting headache for most of the day.

i know ive only took them out for 2 days, i didnt today as being so busy!

But today Felix has been miawing at the frontdoor, going of for a nap, eating, miawing again my head feels like its going to explode

and shes been doing it now, and i want to go bed soon !

When she used to live with my ex's dad she was an outdoor cat and for the past 2 years shes been happily living indoors & i was thinking it will be nice to let her out on the harness, she was good, but now im beginning to wonder if ive done the right thing

ive been crying tonight probably no need to, cause im stressed wherever im doing the right thing!

i was going to try them all again tomorrow, but now im worried if Splodge and Dodger take to it, and they going to be miawing at the door at all hours?

The really good ones been Spice cause shes old ill carry her down the stairs and we go out together, but she hasnt been miawing at the door, and shes used to be outdoors too!

i just dont know what to do now, scrap the whole idea and just walk Spice, but dont know wherever thats fair

i surpose the only solution is let her out, but i wouldnt be able to forgive myself if something happend to her, now tomorrow i dont know wherever to try all 4 again, or leave it.

i must be going wrong somewhere.

some advice would be great thanks!