Hi i'm 22 and have congestive heart failure, the hospital thought it might be from walking pneumonia that spread to my heart, is that possible?

Heart failure: Yes, the bug that caused your walking pneumonia could have caused myocarditis or endocarditis, both conditions could have caused heart failure.

Viral disease: Many pneumonias are due to a viral lower respiratory tract infection. Most, if not all, of the viruses that cause lower respiratory tract infections can also cause myocarditis. One of the outcomes of viral myocarditis is the development of a cardiomyopathy and heart failure. In some cases, the heart recovers over the first few months. Heart failure therapy may enhance recovery.