Boyfriend and one of his best girlfriend

My boyfriend has a very good friend which is also one of his assistants. He told me that he finds her very pretty, attractive, and funny. I do agree, she really is, and you can see all the men around her all the time because she shines beautifully!!! Sometimes when we are having a party, he spends all the night with her, singing, listening to music and they laugh a lot. She sings and I sing too. But when she sings, he says how talented she is, how she could be a famous singer and that he enjoy making music with her more than with everybody else (including me).

I also know that he says very often that I am the woman of his life, he never had a real relationship before me (He was 36 when we met 2 years ago) That I m the first woman he really loves, and he show its in multiples ways, like he made me come in his home to live with him, wanting to have baby as he never wanted that before, presenting me to his family, making me feel at home and everything. So, I know that there is something inside me that I think that I will never have enough proof of his love, because I am so afraid of being betrayed. So, I am working on myself to feel ” I am loved”. But when there is this girl (that I find very very cool and funny and talented and attractive to, so I do really understand), I feel really nervous and jealous . Because I think that if she wanted to be his girlfriend, he would really go into it. She seems really not attracted to him so I am not worried about something happening really, she is only flirting and enjoying the time with him but I suddenly think, “oh, he loves me but he ‘d rather be with her if only it was possible“. And when I feel that, I disconnect immediately with him. I cut the connection to “protect myself from this false love” but I stay with him. So, it’s not a situation. I really have hard time on changing the thought ” if she wanted to be with him he would dive into that immediately because she has so much power on him and, so finally, it means that our love doesn’t count. ” I would love some help!