Several things.

Whilst you dont show the underside of the pipe/nut, it does not look like it should have a seal, it will probably seal on a cone/taper inside.

Joining high pressure oil line with shitty hose and clips, no barbs on pipes etc etc is a recipe for disaster and fire. Do not do it.

It looks like it would be fairly easy to remove the metal EGR pipe to gain some access to the nut...why arent you doing that ?