Any advice for wonky gas gauge

Good morning!

To sum it up, I got rear ended about three months ago and my gas gauge is slightly messed up as a result. The tank will be down to five bars, and after driving 30-40 miles it will go back up to six. Then will skip quickly down to four.

My dad was the one who brought the car to get the estimate, not me, and he said he forgot to mention that it was doing that, so I’m assuming the sensor never got fixed/replaced.

It bugs me but it’s not that big of a deal to me. I’m a little concerned though because money is tight right now and I’ve been going as a long as possible before filling up (as opposed to normally filling up at half a tank- weird quirk but it bothers me if it gets below five bars lol) and I’m worried that it will be showing at one or two bars with no light and then run out of gas. Additionally, if the gas tank isn’t being measured correctly the mpg average is probably wrong too. I know this especially because I would make about 52 on average before the incident and now i average at 48, but I drive the exact same route as before. And the external parts of the car have obviously been fixed so I don’t think that the mpg is actually worse, I think it’s just calculating it wrong.

Anyways, I can still measure my miles on trip obviously so I just wanted to see if anyone had any ideas on how to keep a better idea on how long I have before I really need to fill up. This might be something that would have to be looked at in person for a good answer, but it’s worth a shot. Thanks in advance!