Does he like me or s he losing interest?

I've been talking to an introvert guy (Met through a mutual friend) for over 3 weeks and he always initiates conversations. He opened up to me about his family and things he likes. He checks on me at least once a day but for the past 3 days I feel like he's not trying to carry out a conversation with me. We used to text for hours but now, not so much. He said he's suffering from gastritis so i assumed he must not be feeling well. But I feel bad and I'm scared he'll lose interest in me.

The fact that he checks up on you daily speaks for itself. He is probably very unwell and that is why you haven’t heard from him. If you have not heard from him within a week, check if he’s okay.
If you’re concerned that he has lost interest, you can always talk to him one to one (obviously once he has recovered).

Thank you. I needed to hear that. It's just that I've been so unlucky in love in the past I feel scared to notice the slightest change in somone that I like. I've been creating so many senarios in my head about how bad this might go for days. Thank you for your reply

I've been talking to an introvert guy (Met through a mutual friend) for over 3 weeks and he always initiates conversations. He opened up to me about his family and things he likes. He checks on me at least once a day but for the past 3 days I feel like he's not trying to carry out a conversation with me. We used to text for hours but now, not so much. He said he's suffering from gastritis so i assumed he must not be feeling well. But I feel bad and I'm scared he'll lose interest in me.

He likes you! Coming from a guy, if a guy opens up to a girl about his family, is a huge positive. Also that he checks on you is something a guy will do when he likes someone.

He has already shown interest, it is perhaps your turn to put in some effort too, and reach out to him, and see how it turn out