I have managed to fix mine by getting the solution from another issue and trying it with this.
1. Switch the phone off, leave the sim card in and put inside a zip seal sandwich bag. (I put in inside another one for extra protection from moisture).
2. Put it in the freezer for 45-60 mins. (really, the phone won't break).
3. Take it out of the freezer and the bags and switch it on.
4. Try to activate again, the message might come up again, but this time it let me bypass it.
5. Get to the home screen as fast as possible so ignore any apple sign in requests.
6. When you get to the home screen. Switch the phone off, wipe off the condensation and put place somewhere warm for an hour so there will be no water damage.
It worked for me.
Your "searching problem" will probably be fixed by replacing the antenna.