I need help resetting my cards

I created 3,000 flashcards 5 years ago. I used it for 2 years but have since stopped completely.
I went back now and the card responses are still very long (reference years). I believe the database is broken because it is using the past reference. However, everything is new to me. I wanted to reset it as if it were from 0, but I can’t do it at all. The intervals are always very spaced.

Even after a 2-year break, it’s better not to reset your cards to New. You should expect a lot of lapses, but if you remember things after that long a gap, a next interval in years is probably right! Due times after a break - Anki FAQs

Your best bet would be to set up a “catch-up” deck to deal with the backlog of overdue cards, while you can stay on track with “current” due cards in your main deck.

While you were away, an excellent new scheduling algorithm was released – FSRS. It’s pretty great, and it may make coming out of the backlog easier, so I’d recommend enabling it. Deck Options - Anki Manual

[If you’re not convinced, and resetting is still the way you want to go – you’re right, it doesn’t sound like that card was reset. How did you reset it?]

I am convinced that the right thing to do would be to restart. How do I do this?

How do I make the response intervals stay in days like new cards?

Sure, you can reset all of your cards to New by –

  • Search up all of your active cards, like -is:new -is:suspended .
  • Select all > Cards > Reset.

Each of your cards will need to be re-introduced as New. You will take it through your learning steps, and then graduate it to Review.

Could you be more clear?
I really didn’t find those options

nice, seems like your already answerd

You need to get all of the right cards in view in the Browse window, so search for them. I suggested a search that could work, but you may want something more specific. Searching - Anki Manual

Once you have them, select all of them, and choose the “Reset” action – Browsing - Anki Manual (in earlier versions it was called “Forget”). You’ll likely want to check both boxes.