In general, you are not barred by the post-employment law from trying to influence any federal agency or court on behalf of yourself.  However, it makes a difference if you are acting on behalf of your own corporation or consulting firm.  You should consult your agency’s ethics official for guidance both while you are looking for a job and after you leave the government.  

U.S. Office of Government Ethics’ Post-Employment Summary states: 

The [18 U.S.C. § 207(a)(1)] provision does not prohibit a former employee from representing himself (as distinguished from a corporation 
or consulting firm) before the United States. Moreover, a former employee is not prohibited from acting on behalf of the United States 
(or the Congress).  Thus, even though an individual may once have worked on a matter while employed by the Government, he will not, while 
subsequently reemployed by the Government, be barred from communicating with any employee of the United States concerning that matter 
if he does so as part of his official duties.