How can I strengthen the love between my husband and I and get over the situation with the girl who loves him?

Salaam, I am in a very big Exam from Allah (SWT). I recently got married. I knew before marriage that there is a girl very much in love with my husband (in the family). But despite that he got married to me. In the beginning I could sense that he doesn’t love me. But as I gave him so much love and respect in every single way. He has started to love me aswell. We live in the UK and the girl that loves my husband lives in Pakistan. She calls and annoys us Every single day.. she doesn’t talk on the phone but just to hear his voice. Then Once she said hello to him when he picked up. He straight away hung up but didn’t mention it to me. which made me really upset because I heard her voice aswell but didn’t say anything either. Few days later I confessed to him that I know everything and then again when she called and said hello to him.. he gave the phone to me and I heard her saying hello again. Then I hung up. Since then I have been very upset that she is STILL annoying me and my husband. I want a piece of mind and just want too forget EVERYTHING and give my husband the same love as I used to.. but now I give him rude answers and break his heart. I can see in his eyes that he gets really hurt by the harsh things I say sometimes, but I can’t help it. Shaitan tells me he is not worth my love. Please can you give me a dua so the Love between us grows more and so I can get over the whole situation. For the first time we had a fight today and I don’t feel upset at all.. my mind is saying ‘Good he deserves it’ but my heart is crying tears of blood. I pray Alhamdulillah and I ask ALLAH (SWT) for Sabr and strenght.. but somehow shaitan in my head takes it over. Please Help me. I love my husband to bits and I cannot hurt him on purpose but shaitan makes me hurt him. I am also pregnant and I am worried that this much tension will have effect on my pregnancy. Please Help Me. Jazakallah khair..