So, you died mining tunnels in sand? 5 times right? (That is the xyz that went wrong)
What did you do different "next time"? Cause it sounds like you did the exact same thing (5 times) expecting different results.
That is the definition of insanity, or maybe your char got a concussion and can't remember what went wrong?
Suggestions:
1. Don't tunnel mine in the sand (or gravel) - mine an open pit
2. Build supports - simple frames will work
3. Wear better armor?
4. Wait til you have more health
5. Don't dig so deep - less blocks to fall on your head
6. Accept the game has changed and adapt.