My apple watch keeps losing battery really quickly throughout the day, I have tried turning off background app refresh and closing all my apps when im not using it but it dosent seem to help much. What other ways can I help my battery life. I have Series 7 by the way.
If your Apple Watch Series 7 is still experiencing rapid battery drain, there are several other strategies you can try to extend its battery life:

1. Disable Raise to Wake: Go to Settings > General > Wake Screen, then toggle off Wake on Wrist Raise. This will prevent the display from turning on every time you raise your wrist, saving battery life.

2. Reduce screen brightness: Go to Settings > Display & Brightness, then reduce the brightness level. A lower brightness setting uses less power.

3. Turn on Power Saving Mode during workouts: Open the Watch app on your iPhone, go to the My Watch tab, tap Workout, then enable Power Saving Mode. This will disable the heart rate sensor and other power-hungry features during workouts.

4. Disable unnecessary notifications: Go to the Watch app on your iPhone, tap Notifications, and disable any notifications that you don't need. This will reduce the number of times your screen turns on to display alerts.

5. Turn off haptic alerts: Go to Settings > Sounds & Haptics, then reduce the Haptic Strength or toggle off Haptic Alerts.

6. Use a simpler watch face: Some watch faces consume more power than others, especially those with animated or frequently updating elements. Choose a simpler watch face to conserve battery life.

7. Disable Always-On Display: Go to Settings > Display & Brightness, then toggle off Always On. This will turn off the display when you're not actively using the watch.

8. Turn off Hey Siri: Go to Settings > Siri, then toggle off Listen for 'Hey Siri.' This will prevent the watch from constantly listening for voice commands.

9. Update your watchOS: Make sure your watch is running the latest version of watchOS, as updates often include battery life improvements. Update through the Watch app on your iPhone by going to General > Software Update.

10. Unpair and re-pair your watch: If none of the above suggestions help, unpair your Apple Watch from your iPhone and then re-pair it. This can sometimes resolve issues with battery life.

If you've tried all these suggestions and your battery life still hasn't improved, it's possible that your Apple Watch has a hardware issue or a worn-out battery. In this case, contact Apple Support or visit an Apple Store for assistance.
In case this problem is due to a hardware issue, how can I fix the smartphone myself?
I suggest you contact Apple Support or visit an Apple Store for assistance.

in case you are determined to fix it buy yourself follow the next instructions : 

1. turn off your watch 
2. heat it's back to loosen the adhesive holding it
3. open the back of the watch now 
4. locate the battery
5. unmount the old battery and mount the new one 

be aware if you open it buy yourself you will lose the guarantee on it, and the hardware can be dangerous .