Form 8283

My significant other passed away three years ago.  I am just now cleaning out closets.  I donated a lot of his clothes to two different charities.  I can't file my taxes because it says I need form 8283 that won't be ready until February 13.  I don't have original costs of everything that I purchased.  And both charities did not give me an itemized list.  How do I get past this so I can file my taxes?