Seven years sounds like a long time and, trust me, it is! But it's not overly long in Hollywood time. Projects can be stuck in development for many years. Maybe the script needs work or the topic isn't timely or the lead actor or director can't work on it for a while. Whatever the reason, it can take years for a script to come to life. Forrest Gump took over a decade and a possible sequel is taking just as long.
In our case, we had actually cast the project at one point but couldn't find the financing for it with that group of actors. Financing is mainly driven by the actors you have attached. A-list actors can mean a strong box office so studios and other financiers want to see the most popular actors attached. But this can be nearly impossible for independent filmmakers to achieve. There's less money and usually producers and directors with less credits behind independent projects. These factors can make it difficult to secure an A-list actor.
As an independent filmmaker you have to do the best you can and try to build the most attractive package of talent possible. You must have a solid script or you won't be able to compete for the bigger actors who will attract your financing. So start with a good script and keep your standards high every step of the way and never give up. Many obstacles will be thrown your way. You may have to rewrite the script a number of times or recast the film or find a new director, but if you believe this story needs to be told then try to be patient and hang on through the down times. Remember: Good things come to those who wait!