iMessage wont activate

Hi, i’ve been living in Cali for 5 months now and therefore I bought an american sim card and I’m going home to Sweden in 7 days so I took out my American card and replaced it with my swedish one. But the thing is that my iMessage and FaceTime wont work anymore. I deleted my american nr so i could start texting again but it didn’t work so I went to the Apple store and he told me to reastart etc and then try to activate my iMessage again but it wont!!! It just says ”waiting to be activated” and has Been like this for 6 hours now. I really need To be able to use both iMessage and FaceTime, what should I do?