I am sorry to hear that you can’t send images via email without them getting blurry.
If you are sending iPhone to iPhone, please follow these steps:
1) Open your Settings app on your iPhone.
2) Tap General.
3) Tap Software Update.
4) If there is an available update for your iPhone, tap Install Now.
5) Plug your iPhone into power (cable or wireless) and wait for it to show your Lock Screen.
6) Log into your iPhone.
7) Open your Mail app.
8) Send a Test Email with a Photo to your other email address (if you have one).
If you do not have 2 or more email addresses, try sending your test email to one of your friend/family member’s email address.
If these steps did not work for you, please reply to me.