We need to use “too” (not “to”) as an intensifier.
2. Modifier use:
“Much” is used to modify uncountable nouns. Since “people” is countable, you should use “many”.
3. Plural form:
“People” is already plural (unless you are referring to something like a racial group), so it doesn’t need to be pluralized again.
4. Passive or active voice:
Do not use the passive form (“was hurried”) unless you mean to suggest that something was causing the speaker to be hurried. In this situation, use the active voice.
4. Modifier use:
To convey the extent of the modifier, use “so” (not “too”)
5. Apostrophe error:
“Shirts” is plural, not possessive, so there is no apostrophe. “Bought” is the past tense of “buy”, so it should never have an “s” or an apostrophe.
6. Subject-verb agreement:
Since ‘shirts’ is plural, you need the plural form of the verb (“are”).
7. Verb tense:
The present progressive (“am having”) would indicate that the action is happening now. It’s better to use the simple present tense (“have”) or the simple future (“will have”).
8. Punctuation:
When a coordinating conjunction such as ‘so’ separates two independent clauses, use a comma before it. When there is no coordinating conjunction, you need a period or (if the ideas are very closely related) a semicolon.
Possible solution:
There were too many people in the mall, so I hurried with my shopping; I was in such a hurry that the shirts I bought are not big enough, and I will have to return them.