Sorry, this might be long...
Persuade mum to treat you to a first class hair salon. At these places are albums of a variety of hairstyles, and hair artists varying from junior to senior hairstylist. And prices vary accordingly.
You have what I see is quite thick, luxuriant hair. A skilled hairstylist will thin it out, expertly layer it and to the style you want. As summer will soon be here, you could consider having your hair shortened to just touching your shoulder? Like mine. With enough left at the back to ponytail up sweetly when you’re wearing a hat.
Tinting your hair can cost a lot of money, depending on what you prefer. Stick to colours that compliment your skin tone. Ask mum to help you decide if you're better off with single-process colour or highlights. With your hair being so lovely anyway, maybe blonde highlights would be better? Rather than go for a complete colour change, choosing blonde highlighting means you can always add more later when your hair has grown back. I suggest you stick with the same hairstylist/franchise because then the person who cut and styled your hair is more likely to remember you.
As a guide price, when having colour put in, such a treatment including wash, cut, highlight and blow-dry could be ballpark £90.00 down to around £48.00. Second visits will cost less once you have set out on an established new hairstyle.
Your mum will be proud of your new look, as will you. You’ll feel different, and you’ll be much happier.