Felt + present/ past (back shifting ) [duplicate]

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

1. I have no past (simple present): this is the current state of things. Perhaps you once had a past, but the celebrity's glamor has knocked it from your memory. As time moves forward, you may retain the new past. Or not.
2. I had no past (simple past): The celebrity's glamor is so strong that you feel that you never had a past and you just now sprang into existence.
3. I have had no past (present perfect): The meaning is the same as 2 (simple past), but you're referring explicitly to a time interval that stretches from the past to right now.
4. I have no future (simple present): The celebrity's glamor is so strong that you know right now that your existence will cease when the celebrity leaves.
5. I will have no future (future): The celebrity's glamor is so strong that you predict that it will come to pass that your existence will cease when the celebrity leaves.

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

1. I have no past -> I had no past. (backshift to past)
2. I had no past -> I had no past. (no backshift)
3. I have had no past -> I had had no past. (backshift to past perfect) The explicit present perfect interval (past up to present) has become an interval starting sometime in the past and going to the past time of your feeling. That's what the past perfect is for.
4. I have no future -> I had no future (backshift to past)
5. I will have no future -> I would have no future (backshift to past) Because part of that future, from the feeling to the report of that feeling has already happened.