I wouldn't worry if __________.

Second Conditionals এর নিয়মানুযায়ী, 
- If যুক্ত clause টিতে Past Simple tense থাকলে, অপর clause টি Future in Past (S + would/might/could + Base Form of the Verb) হয়। 
- Structure: If + past simple >> + would + infinitive. 

Examples: 
- If we had a garden, we could have a cat.
- If I won a lot of money, I'd buy a big house in the country.
- I wouldn't worry if I were you.

উল্লেখ্য, If এর পর যদি be verb থাকে, তাহলে 'were' ব্যবহার করা Grammatically correct.