I haven't been to Tokyo, but I wanted you to get at least one answer. I hope you are feeling better.
When I was thinking of going to Japan (haven't made it yet), I found there are Japanese university students who want to be your guide (for free) just so they can practice their English. No doubt you would like to talk to a friend or someone you know, but maybe you could connect with one of these young people.
If afraid of getting lost, what if you budget (I know it's a ridiculous price) as necessary for a cab ride back to your hotel (and carry a hotel address card with you)?
For a solution that some might consider ridiculous, how about staying at a hostel? Then you would meet Westerners in a friendly setting and you might find someone to go on outings with. Or maybe you could even just visit one without staying there. There has to be some place to meet fellow Westerners.
How long are you in Japan for?