Accord 2000 v6 3.0L EX - Gas tank couldn't hold a full tank - Gas gauge acts strangely randomly

[DeafGuy13]

Every time the gauge says nearly full, halfway or nearly empty- 
If it was one week and half ago, i know i'll need to refuel up.
If it was 3 days ago, or just yesterday - this is when i find it really strange. It wouldn't show the gas gauge full, just barely "nearly full" or halfway until i drove over like 10-15 miles, then it'll somehow "recalibrate" itself and shows the correct amount of gas, which is random. Sometimes it'll show the same until i turn it off, and then come back to turn it on when i want to drive to somewhere, it'll show the correct amount of gas.

As for refueling process, I tried my best to try and fill it up whenever it can, but it would be short very quick, like the bubbles will comes up immediately after a minute of refueling. It goes down, i try to refuel, and it comes up, and repeats until i stops trying to refuel.

I'm considering on rebuilding/cleaning the fuel pump itself to save money or go all out and buy an new OEM fuel pump to see if it'll fix the weird issue. Either that or that get new upgraded and improved gas tank. 

Let me know what you guys think