Jealousy is bad for any relationship. It is unpleasant, anxiety and anger producing and at times, embarrassing. If you continue to let the jealousy and anger fester it has the potential to seriously damage your marriage. It is good that you are amenable to taking steps to correct the problem. That is very encouraging and it’s a good place to start.
It’s not fair to be angry at your husband for activities he engaged in during a time when he did not know you. His history should not be a factor in your current relationship. What he did before he knew you is history and it should stay that way. History cannot be changed. Most people would probably change many things about their past if they could but they can’t. They must accept that fact and move on. It is the reality of the situation.
You’re particularly upset about the fact that he saw semi-nude or naked women dance at the strip club. Apparently you are comparing yourself to girls at the strip club and coming to the conclusion that because he has seen them naked they are better-looking than you and thus you are inferior to them. This is jealousy. This is you not feeling good about yourself or your body.
These feelings of inferiority are emanating from you. They have little to do with your husband. Your husband did not make you feel this way; you felt this way on your own when you heard about the strip club.
If your self-esteem and self-confidence are low or nonexistent and you are aware that it’s negatively impacting your marriage then you need to find a way to correct this problem. As you mentioned, you are the one feeling unloved and unhappy. Your husband does not seem to feel that way about you.
Therapy can help you to change your thinking as well as change your behavior. If you do not want to try therapy you could also try self-analysis.
Self-analysis would start with you being objective about your situation. Here are the facts as I see it: you have a husband who loves you and in your words, “believes in you.” He seems to be acting in a manner consistent with a husband who is devoted to his wife. You did not say that he spent time surfing the net for pornography or going to strip clubs. He went once to a strip club and if you asked him, he would probably say that it was a non-event in his life.
The goal of self-analysis is to be able clearly and accurately assess the situation and to think through how you could correct the problem. It requires that logic, and not emotions, leads to an understanding of the situation. If you are having difficulty with self-analysis and feel you need an outside, objective opinion, consider seeing a therapist. It could save the relationship as well as your self-esteem.