I would like to get over it but just do not know how...

Hello everyone, it's stella. I am dealing with anxiety and obssessive thoughts for a while. I was always anxious but this sticky, uncomfortable feeling has started 2 months ago. I am getting married and me and my fiance rent an house. After moving our New place I started to feel like I am swiming in a sea of problems. Our new home is great, just like we have imagined. He is kind to me. However, something inside is always telling me something bad is going to happen. I am feeling very anxious if his mother comes to our home and do things I do not like, just like treating like its her home etc. I feel like his parents are so sticky and I am so anxious about it. But the point is: they are living in another city and I know that they wont be in our home always. The problem is in my mind, I cannot get over these negative scenarios in my mind. I really need help and in my country there is a lockdown atm and I am at home... These thouguts and this anxious feeling is really killing me. I know that might sound crazy feeling this way when actually there is no specific problem. But I feel this way. Waking up with negative thoughts and sleeping with them...