Phone keeps disconnecting and reconnecting from cellular and sim card?

My phone has been recently going crazy, i have an Iphone 11 and it just recently started to give me problems with my sim card and cellular connection. (I should also mention the lightning port on the bottom of the phone stopped working a few months ago) But just recently i woke up in the morning to see that my my sim card was locked. I didn't touch and settings or anything it just locked itself. I had tried taking my sim card out and putting it back and even tried a new sim card. I had to go a whole day without data and find my way around to different job sites without any directions. (WHICH SUCKED). Finally, i tried taking my sim car out and putting it back one last time and it fixed it, but now it'll randomly lose the sim card and i have to take it out and put it back in over and over again. Sometimes it'll hold for 5 hours, sometimes i'll have to do it again after only 2 minutes. And to add onto that, now it's just going from LTE to No Service over and over again, i haven't even moved from the spot i'm in. Is there anyways i could troubleshoot this or is it just time for a new phone? I really don't think a phone that's only a few years old should be broken this badly.