I'm a reformed sex addict but have had periods of no libido whatsoever ( due to depression, l later found out) and now have a high sex drive but do not have the sex addiction any longer.
You ask how to tell if you are a sex addict or not? From the main body of your question it seemed to me that you were just highly sexed but then I got to the last line :I am afraid to go to a place because I am thinking that I will want to hook up with someone there and have sex with them.

That line in itself may indicate a sex addiction depending on what that fear is based on, and how much that fear intrudes into your normal life.
In my mind, any addiction is easily identified as it is behaviour that gets in the way of having a 'normal' existence. If you are feeling horny and you have sex 20 times a day and feel great, and it doesn't impact negatively on your life or the life of your loved ones, then hey go for it! But, if you feel you need to have sex compulsively despite the ramifications and disruption it may cause to the rest of your life and your family, then that is a clear indication of an addiction.

My experience of sex addiction was that it was my way of trying to comfort myself after painful emotional incidences. I would reach for the phone to call someone to come over absolutely compulsively , but then never actually enjoy the encounter. I would reach orgasm but feel horribly removed emotionally and would often cry afterwards. I would always regret the encounter, but that in turn would lead to a vicious circle of my feeling low, then reaching for the phone once more.
It was only when I shared this with my sister ( who self harms) did I realise that that my behaviour and feelings leading up to the compulsion matched hers before she cut herself. I used a different implement to harm myself ...

My addiction came from a non sexual root, my early years relationship with my mother who has NPD.

I've now explored and come to terms with my past, and my sexual addiction has evaporated.
In its place is good self esteem, access to intimacy and a healthy , loving, fulfilling sex life.

Good luck, it's a long hard journey ahead, but it's worth it.