Young children are very awear of and pick up on adults fears and attitudes about things.....but Please do not be hard on yourself or feel guilty for this as you did what you thought was best in keeping your child safe. This is a problem that with time, patience and a little work can in fact be turned around.
I would start off with taking your son to the mall and playground during hours you know these places aren't busy and slowly work on the fears with him.......
At the playground let him watch you climb the same things he's afraid of...go up and down, laugh and make it look like it's a lot of fun to do. Don't prompt him to join you, just let him watch and get used to seeing you do this....after several times of this... Then bring him to the playground when it's busy...together just watch the other children climb...say positive things like "gee, these children seem to be having a good time climbing." "Oh look at that one, he's hanging upside down, how wonderful" etc. etc. Still don't prompt him to try...just watch. Then one day bring him to the playground during a time when it's not busy, better if it's empty.....climb something he is afraid of, come down and invite him to join you. If he's not ready to try, don't push it...If he's willing to try, take it slow and easy...stay a long side him and stop when he wants to stop and safely take him down. Tell him he did good and ask if he'd like to try again...if he says no...don't push it.. Each time you go and work with him, you should see some little improvements...tell him how great he's doing. Know the process will take time... Also take him to the playground when it's busy as well and let him just be. At some point he will totally surprise you...
At the esculator pretty much do the same but go with a friend who has a child the same age who's not afraid if that's possible. Stand with your son on the bottom of the esculator watching your friend with her child riding up and down several times. Then ask your friend to stand with him while they watch you go up and down....smile and wave to him.. Then try putting both children on the same step to ride together...Your friend on one step in front, and you one step below...with your hand on your son so he knows you are right behind him. When your done doing this, tell him how proud you are of him. Treat the children to ice cream or something they like and remember the process with this will also take time....
The more you practice and do this with your child, he'll begin to see and understand you aren't afraid, and he will begin to experience himself that there is nothing to be afraid...just take it slow.