Hi One N, welcome to OSM! To undelete a deleted node you have do a revert of your changeset. This can be a little daunting so I went ahead and performed the revert just now, undeleting [https://www.openstreetmap.org/node/8665958771][1] with changeset 117484826.
If you find yourself in this situation again, you can try the [RevertUI][2] tool. You'll need to know the ID number of your changeset that deleted the node, not the number of the node itself. This process can be intimidating for new mappers, and in fact has the potential to cause a little chaos, so feel free to ask for a revert here again if you need. (You can also message me directly from [my OSM profile][3] -- I'm a local NYC mapper so I'm happy to help with this, or any other questions you have!)
Happy Mapping, Jmapb
[1]: https://www.openstreetmap.org/node/8665958771
[2]: http://revert.osmz.ru
[3]: https://www.openstreetmap.org/user/jmapb