Erections and condoms

Hi there, new member here trying out the free trial and figured id come straight out with my current issue. My fiancee and i recently had our first baby, about 6-7 weeks ago now.

There was obviously a gap in our sex life over that period as she was too sore etc. Now we’re back at it, we need to use condoms as we dont plan on having another child, but i find they seriously affect my performance.

I can get erect to put the condom on and stuff and start sex fine, but as soon as the actual sex stops for a second to change position or reinsert i immediately lose the erection and trying to get up again with a condom is difficult for me. Do you guys think the condom is the issue or is something else going on? Our sex life is still amazing and she doesn’t complain or anything, its just very awkward for me going from full sexual energy to trying to make it work again with a tight uncomfortable condom.