Relationship and mental health

Me and My boyfriend have been together for almost 4 years now he really is my one true love I never thought I'd find love again as iv been hurt in the past.. just over 2 years me and my boyfriend found out we was pregnant we was so happy but things turnt for the worse and I had a misscarridge. Really broke me.. for a long while now iv suffered with anxiety, jealousy worry and feeling okay one day and good the next I'd say once a month when I'm due on my pms is quite bad.. iv talking with a therapist and the more I think back to how these feelings started I feel like it started after I had a misscarridge. Can something like that cause these feelings?? I never use to feel this way I'm so worried all the time and worried uf my boyfriend will leave me even though there's nothing to say he will I just always think the worse does anyone experience this? Or no what I can do to get back to my normal self ? Many thanks x