I'VE FIRST CLOSING DATE AS PER CONTRACT ON FEB 28 IN NJ, WHICH EXTENDED ON MAR 8, I GOT COMMITMENT LETTER ON FEB 23, WHICH I'LL SEND BACK AFTER SIGNED ON FEB 28 TO LENDER, LAWYER SAYS SOME THING WRONG WILL HAPPEN(SELLER CAN SUE ME), THIS LENDER CANN'T FUND MONEY ON MAR 8.
MY QUESTION WHAT WILL HAPPEN IF LENDER WILL NOT ARRANGE FUND ON MAR 8.
WHETHER I CAN PROTECT MYSELF FROM COMMITMENT LETTER FROM LENDER?
CAN SELLER EXTENDS THE CLOSING DATE.

Any date can be changed with mutual written consent of both the Buyer and Seller.

addendum to above part:
My lawyer says in an email if I'll go against his reffered mortgage company, I'll be sued by seller, who is charging $200 more per month in my payments than my credit union company, which i'm member and have the commitment letter.

Sound like the lawyer isn't your lawyer... he is steering you to a less desirable mortgage company.

This lawyer may have some reciprocal relationship with the mortgage company which in most cases is considered illegal and even if not, if he attempts to force you to use them he is in violation of his fiduciary duties.

See if he will give you in writing why he thinks any suite is possible. He appears to be taking advantage of you.

Why are you even working with an lawyer? Why are you not being represented by an agent?

my lawyer and my agent both are friends.
what could happen if lender will unable to send check before or on closing date and
If lawyer will not present himself on closing date?
Will this better to contact my realtor company's(big one) manager's help to get close this deal from my lender without interference of my lawyer?
Or shall i change the lawyer at this moment?

Note: I am not a lawyer and the following is not legal advice.

You should find a neutral lawyer. In other words, find a new lawyer for a second opinion on your situation, which sounds confusing. It could be all that stress.

Your lawyer might be explaining your legal liability if you back out of the transaction.

As far as I am aware, there is a difference between intended breach and involuntary breach of contract. You might lose your deposit if you don't close.

If there is a delay in closing, usually the seller and buyer could agree on an extension, but there is no guarantee of an extension. There could be circumstances that could cause no possibility of an extension. Escrow might have to figure additional interest. The lender might have to charge you extra money to keep your locked rate. There are so many factors.

Suggestion: get your paperwork together, review your contracts and call your lender or mortgage broker and find out what is going on with the approval process.

You should not have to worry. If you are worrying, you are missing some information.