hi Pierre, welcome to the community. I joined here in 2008, and scar tissue was a big deal for me. I too was hesitant to try new places, and other TuD members encouraged me and gave me the courage to try.
For a while I even wrote down where I put the sets, just so I wouldn’t go anywhere near in a 30 day period. It really helped.
if you need a little assistance, ask your doctor to order you a prescription of EMLA cream, you won’t feel anything from the inserter needle. another suggestion is if you use a insertion device and have a partner to help you, you can ask them to do it just a bit father away from where you can reach.