Um -- do you even hear what you are saying?? Didn't think so.
You cannot "dye" hair lighter. Dye means to ADD more colour to make something darker. Period. You cannot make anything lighter with a dye. Understand that first.
To make anything -- fabric or leather or hair -- lighter, you will need to REMOVE colour from it, and that means bleaching. There is no other way. Think about that.
Your jet black is all cut off now after 3 years. Since you have dark brown hair (not black), you will lighten it a little to a reddish brown/orange colour. Then you will need to lighten it further to get all the orange out of the hair, and then add a brown at the level you want. If you want some red-gold in your brown, then you don't need to lighten your hair that much. Yes, it is a two-step process.
Sometimes, you can be lucky and use a bleach (or a light blonde tint) and you will end up about the right level of brown and be happy with that. You won't know until you do it.
Remember that ALL permanent tints contain bleach in them. Any hair colouring you buy off the shelf will have some bleach in it...even the jet black. That is how they have to do their job. They lighten your hair a little, and then add the artificial colour, all in one application. But to get the exact right shade you want, you have to do it in two steps.
This is not really hard to do, but does take some time. And you would need to know what you are doing, and have some experience -- which it appears you do not. I would strongly suggest that at the very least you have a consultation with a qualified professional hair colourist (no charge at most salons) and get some advice from them. They can do a proper analysis of your hair to see if you can get the shade you want (please take in pics of the exact shade you want) in one step or two. They will tell you how they would do it, how you need to care for your hair after, how often you will need to get retouches, etc. Be sure to ask how to get rid of it should you change your mind. After that, go home and think about it, and then decide what to do. This is a permanent change so you don't want to do it "just for fun" without knowing the full cost.
No, black plus light blonde do not make brown.