Is he the right one???

So me and my boyfriend have been dating for a month and we talk every day and he makes me super happy and he keeps my stable when I'm mentally not ok but I've been getting this feeling that hes gonna leave because I've constantly been left with no explanation and I dont know if it's ok to be happy because I never know what it's like to be happy in a relationship because my past ones were so toxic I really dont know what to do and I see a future with him but I feel like hes going to leave he tells me he wont but I'm so scared that he will