Am married hen of 33 years...
There are no downsides whatsoever!
If you two are in the relationship for the long haul, keeping the sex fun and interesting is perfect. This is how relationships last. No hangups, no insecurity (sounds like you're doing just fine with that..) just fuck each other silly into the mattress, the sofa, the kitchen table.. wherever!
It's not about what you've got, it's about what you do with it and YES, enhancements are totally fine. Go be the sex-beast you are and have fun!
Mad props to you kid!
It'll be awkward at the start, but a good therapist is primarily someone that listens without judgement and after a time, will offer suggestions on how you can address the issues bothering you.
They're not generally cold and calculating, that stereotype is decades out of style.
What you'll find is a space you can talk.. and before you go in, ask YOURSELF what your end goals for the therapy are and make a list of the points and ask the therapist if they can be realisitcally achieved, but don't expect a direct answer for that at first. The therapist needs to get to know you and your issues a bit first.
Ultimately, all of it will be down to you, and no one else.
A good therapist - be it a psychiatrist or psychologist (I prefer the latter) will get you to see what is holding you back and center you ON you.. not in a narcissistic way, but see the whole person - good and bad - and learn to work to open yourself to change.
Remember, it will take some time, and the changes a therapist makes are in getting you to see your own strengths and weaknesses and how to avoid the pitfalls that people often put up in front of themselves when trying to better their lives.
Guilt, trauma, self-doubt.. that shit is real and the best therapy gets you to see where the baggage lies and to let it go.
The therapist you find may be awesome and you click instantly or they might not. If not, don't give up, move on to another person as every therapist is different and has different approaches to getting you to open your head to yourself.
I was in counselling for years as a teenager and it really helped me cut through my own insecurities and stop me doubting myself and got me the courage to leave home when I was 18 - with rocket boosters on, even though it sucked BIG TIME for years afterwards. (oh how it did!) It was all on me and I turned out ok in the end.
Therapy is a process, the main thing is to not bullshit yourself about any given situation, no matter what.
As to privacy, HIPPA laws still apply, and there is also nothing stopping you from asking about how robust their privacy controls on patients data are. Ask for paper copies of the records for yourself, that way you can have them accessible at a later date w/o having delays as the older records are fetched, if you need them. You DO have that right.