I've been starting to do some internal work on an issue that was brought to my attention by my significant other. I also decided to book an appointment with my therapist. Back when I was doing the Emptiness working, my ex told me near the beginning of it that she needed me to go see a therapist as I worked through it, because it was clear to her that I was digging through a lot of emotional wounds. She was right. Since that time I've realized that while doing internal work is important, having someone to go to share that work with who isn't emotionally involved is also equally important. An objective perspective can help you keep on track and also help you deal with the rough times that inevitably occur as you deal with the internal work. A therapist can provide that, provided s/he understands the kind of work you are doing.
It is important to explain what kind of mediation you are doing, how it works etc., so that you can provide some context for how you are arriving at the conclusions you have.
The therapist I go to has been invaluable for raising perspectives and helping me understand some of the emotions that have arisen as I've dealt with my internal issues. The meditation I do has helped me unearth those issues, but having the therapist available has helped me make sense of them and come to a place of resolution with them. So if you're doing a lot of internal work, it can be useful to also see a therapist in conjunction with the work you do.