Do you know specifically what caused the vaginismus or when it first appeared? For instance, did you experience a trauma as a young teenage girl? Or is this more the result of generalized anxiety, depression, with an unknown cause? I think this is an important question, to ask yourself, as it will determine how to best approach the problem, and whether therapy may help, and what kind of therapist to seek out.

You say you feel as though you are a teenager stuck inside an adult body, that might point to something in your past that caused you to shut down and close yourself off at that point in your life. Maybe it was a traumatic event. Or maybe it was a feeling of rejection, isolation, or self loathing. You mention feeling responsible for a friends recent suicide. That is undoubtedly a traumatic experience, you are now left processing. Whichever the case, I agree it's a good idea to revisit a memory or time where you last felt like yourself, and begin to heal and develop yourself.

As someone who has dealt with a lot of sex anxiety in the past, I do think working with energizing/nourishing masculine energies and learning to develop a positive feminine self image as well, is on the right track. This did work for me. This will also pave the way for more positive interactions and opportunities with men you meet, and future relationships.