A few months back I met a celebrity and seeing his glamour I felt that I have/had no past or future.
Which is to be used, had or have ?
Before you can tell what tense to select in your reported speech, you have to know what you meant at the time the event happened. I can think of five things that you might have been feeling at the time:
I feel that
Now, we can consider what tense to use when you report that feeling in the past: "I felt that." Tenses and time are closely related but they are different. Ordinarily, for things that remain true or things that are general truths, backshifting isn't required:
Galileo felt that the earth moves around the sun and not, as the Church taught, the other way around.
But your example sentence explicitly ties the tenses to past, present, and future. In particular, your statements about the future affect how to consider the enduring actions in the past. But let's try anyway:
I felt that
Often I notice people using present tense even if what was said is no longer true. Example : "A month back I met a man but I felt that I am in bad clothes, therefore I didn't meet him."
Here are two slightly different versions of this:
A month back I saw my professor walking toward me on the sidewalk, but I was in my dirty work clothes, so I ducked into a coffee shop to avoid him.
A month back I ran into my snobbish neighbor downtown. Whenever I talk to him I feel badly dressed.
For many of these examples, both tenses would actually work.
If any more example sentences of this very issue come up later that you find confusing, please add them HERE in this thread, and get my attention with "@aparente001" in a comment. Sometimes the question feels answered, but then a month later a follow-up question arises.