Mobility aids/custom wheelchair

Hello so I think I am at the point of needing a mobility aid, I have used a cane before and it greatly helped but I was still so worn out after an hour. I was wondering if anyone had recommendations of online wheelchairs or rollators/walkers or what was the process between you and your doctor of getting a custom made chair? Like what did you ask for, how did you bring it up? I’m worried my doctor thinks I don’t need one but I feel like i would be able to do more for longer