First of all, don’t stress about explaining “what’s wrong” to a therapist before you meet them, or let this become a barrier to you getting started (I fell into this trap for years myself). A simple “Hi my name is X and I’ve been been thinking about finding a therapist to work on some issues with. When would you be available for an initial call?” is perfectly sufficient.
A thing people say about therapy is that it’s like a bit like dating. Don’t be discouraged if it takes a few tries to find someone who is accepting new patients and feels like a good fit (most will offer a free consultation as well to help you evaluate this). Give them a fair shot, a few sessions at least (I was skeptical of a therapist I was randomly assigned ~10yrs ago, but he swiftly cured a very acute case of hypochondria that had bubbled up out of nowhere. However, you should move on to the next one if it really isn’t working—unlike dating, your therapist won’t be hurt (or if they are, then they have the tools to deal with it right?). This is probably the best directory for finding local therapists: https://www.psychologytoday.com/us/therapists
Most will give you a set of questionnaires to complete before or during your first appointment (e.g.: https://www.uwgb.edu/UWGBCMS/media/Continueing-Professional-...). This gives them a coarse baseline of what’s going on.
The conversation simply evolves from there. Over time, you will occasionally pull out surprising memories and insights from the depths of your mind like the proverbial Mary Poppins bag. There’s a lot in all of us to unpack, and they are there to facilitate that process.
A common attitude (again, one I’ve suffered myself) toward therapy is: “What will a therapist tell me that I don’t already know? I can solve these problems on my own if I actually tried.” Maybe, but the operative word phrase here is “actually tried”. Actively reflecting on your thoughts/emotions/actions and vocalizing them to another person for an hour is challenging, but it is therapeutic in and of itself. It’s very hard to do on your own, and sometimes take a probing question or two to dislodge a blind spot.
Also, if you want to listen to some real therapy sessions (intermixed with lecture content on the theory and research behind a common type of therapy), these lectures on Cognitive Behavioral Therapy are excellent. It follows a few different people from the very beginning (skeptical of or unsure about therapy or what their deeper issues are) through their process of improvement via weekly sessions/assignments. It can really help demystify therapy for the unfamiliar: (https://www.audible.com/pd/Cognitive-Behavioral-Therapy-Audi...)
PS—Keep asking good questions.