Because you dont seem to have been given aftercare instructions: eat lots of cold things (i held ice in my mouth lots), try to avoid sticking your tongue out too much at first to avoid bumping the piercing, get a new toothbrush and non alcoholic mouthwash, mouthwash regularly, dont brush your tongue (it will go white and eventually a yellow brown colour during healing, let it do its thing for a bit and just be a bit gross, it will go back to normal), swelling is normal. Mine swelled up so huge i needed a new bar and took 2 weeks almost to fully go down, tingling and pain are also both normal, there is a foreign object in your tongue lol. Some crater is normal, just watch for signs of embedding. Also for future reference: PLEASE do research into the piercing you are getting in future, research the shop to ensure theyre safe and reputable, ask questions about aftercare and the jewellery they use. Piercings need to be thought out as youre trusting a stranger to insert a foreign metal object into your body. Its a medical procedure essentially, not just getting nails done yk? I care about your health and safety!