Please give me some advice?

I met this guy online and it really kicked off really well. We chatted day and night about everything and dreams or goals even making how we would you know have a future together till six months this was really going on going well but I was not so much involved because I didn’t really trust him at that point so I was a bit reserved but I used to share my thoughts.
Then this pandemic happened and we couldn’t meet because we are staying in different cities in the same country and we are in the same profession so recently I asked him whether he wants to be serious with me and he said he doesn’t want to be serious with me which I felt a bit sad about then I started you know cutting him off saying that I am busy and I am can’t talk to you even if I meet him angry so that he doesn’t talk to me he would still after a month try again.
During our talks on physical things he would always talk everything with me and I asked him whether he was just talking he was talking to me only out with other girls and he said that he was only talking it with me and he would keep it that way I am really confuse like he is not serious about me but he is obsessive mean he wants he wants to talk only with me what physical stuff which I feel is a bit confusing and disturbing.
So please help me out as to what to do should I you know just block him or although he has been a good senior to me yes help me in my professional life but I don’t know why he is so he just wants me so please tell me some ideas
Please give me some advice?
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