I have to ammend becsuse i recieved A 1099Misc late from a contractor. Can i write off my expenses and issue a 1099MISC to the contractor who helped me do this job??

Yes you do all of that...and NEXT year just report all your income, expenses & file 1099-misc forms on time by using YOUR records. You never need to wait for any 1099s to arrive to file your return . 

Now the person you are going to 1099 will need to amend their return if they were not smart enough to file correctly .

I claimed my part under other income because I hadnt recieved it. But the contractor sent whole job on 1099 to me instead of spliting it up between me and the other contractor. When I asked why it was so much he said i would need to issue 1099  im not paying taxes on $7500 that another contractor recieved.

If you were paid the entire amount then you paid the sub contractor then you needed to enter in the entire amount on your return then 1099 expense his portion.

If that sub contractor  was paid by the client directly then they should have not given you  a 1099 for the entire amount ... only your amount should have been on the 1099 ... this should be corrected by the client ... or you can just take care of it as you are proposing to do.