I think therapy can always be a useful place for growth-- but then I'm studying to be a therapist so I am biased.
I will let you know that there is a big divide in the sex therapy community about the term "sex addiction". Most sex therapists don't believe in being addicted to sex-- although one can use sex (sometimes unhealthily) to cover up for other issues, and one can be exhibiting out of control behaviors (drinking, lying, etc) that are done in conjunction with sexual behavior.
Many times people will latch on to the idea of "sex addiction" because it is an easy way to make something an "illness", or something "beyond one's control" that you can get help for. It's easier than, say, looking into the individuals, their pasts, their relationship, their communication styles and how all of that affects their sexual relationship.
And often, when there is a discrepency in desire between partners-- the term "sex addiction" comes up to describe the individual with the higher sex drive as if that now "explains" it and now we have a problem that can be solved.
I say this knowing that I know nothing about your specific situation. I will tell you that most therapists (especially sex and couples therapists) get many people each month coming in having diagnosed one of the partners with "sex addiction" or "porn addiction", etc. It's the new catch phrase for sexual disorders.
I'd say, rather than go in with a self-diagnosis, just go in with the issues at hand. The therapist will be able to ask questions and get more information and help you with figuring out what you need. Good luck!