I do not think you are being needy or insecure. I also don't think that you are expecting too much. You said that you both were texting a lot in the beginning, so I would think after meeting and having 3 good dates the texting or conversations should increase at least by quality if time restrictions play a role. I can not say if he lost interest. It could be he is under stress or busy at work, but actions do speak louder than words. Normally, he should want to and if can not he should be expressing that to you. However, in this day and age sometimes things are not what they seem and people do strange things for strange reasons. I would see how it plays out over the next few days. If it continues I would try talking with him directly. Not in an angry fashion or judgemental, but more a concerning fashion interested in knowing his thoughts and feelings. Communication is best!
I wish you the best and please let me know if I can be of further help.
That depends. How were you able to know? Also, are you still part of the site?
If you want you could mention that if you decide to discuss with him about how you are feeling. You can say you checked and saw him there. However, I would not recommend saying that at the beginning of the convversation. I would hold on to that and use it only if you feel the need to question him depending on his responses or save it for the next time if you discuss and he doesn't make any change. I would start with his visible actions and the way you feel.