Hi BabuBear735,
Thanks for posting in the Apple Support Community. I understand the volume bar on your iPhone is staying on the screen even after restarting and that the volume keeps going up. I can see how this would be really inconvenient for you. I'm happy to help.
You've already tried some great steps. I would like you to reinstall iOS on your iPhone. This should not affect any of your data, but it is always a best practice to make sure you have a current backup in either iTunes or iCloud. How to back up your iPhone, iPad, and iPod touch
Once you have a current backup, follow the steps in the section titled "If your device turns on but gets stuck during start up" from the following article. These steps will reinstall iOS. Keep in mind that these steps were written for a different issue, but they will still help us isolate the situation further. If your iPhone, iPad, or iPod touch won't turn on or is frozen
Take care.
Thanks for posting in the Apple Support Community. I understand the volume bar on your iPhone is staying on the screen even after restarting and that the volume keeps going up. I can see how this would be really inconvenient for you. I'm happy to help.
You've already tried some great steps. I would like you to reinstall iOS on your iPhone. This should not affect any of your data, but it is always a best practice to make sure you have a current backup in either iTunes or iCloud. How to back up your iPhone, iPad, and iPod touch
Once you have a current backup, follow the steps in the section titled "If your device turns on but gets stuck during start up" from the following article. These steps will reinstall iOS. Keep in mind that these steps were written for a different issue, but they will still help us isolate the situation further. If your iPhone, iPad, or iPod touch won't turn on or is frozen
Take care.