imessage number grey, not able to use imessage/facetime

Recently, I have not been able to use FaceTime or iMessage to communicate with my boyfriend. The only form of communication I can use with him using my basic phone properties is voice call.

In the settings for iMessage, my phone number is grey under "You can be reached by iMessage at" and there is a grey check next to it while there is also my email which is dark and has a dark check. My phone number, however, is dark under where it says "Start new conversations from". I don't know why one is grey and the other is not. A while ago both my phone number options were grey, and my emails were too. I cannot text or iMessage this one person but can with everyone else.

I have tried restarting my phone, turning off iMessage and FaceTime, resetting my network settings, taking my pin card out, and signing out of iCloud. Nothing has worked.

Note: I have an iPhone 5C with T-Mobile 28.5 and am unable to update my iOS (10.3.3)