Penetration issue

Hi guys! I wanna ask about something that has been bothering me. So me (22f) and my bf of 3 years has tried to have sex for many times. I used to think I had vaginismus because I have never really inserted anything inside my vagina and was afraid of pain. But recently I found out I can insert one finger easily with no pain and 2 fingers with a little uncomfortable feeling of being stretched to max. But when we try to have sex, it never ever goes in ,like literally not even the tip. When he tries to push inside I feel a growing stinging pain. What should I do guys? What’s wrong with me?? Is my vaginal opening too small . Please let me know if you had similar experience and how can I improve this. My man is very patient but my condition is affecting me emotionally a lot.