Afraid of losing people

I'm new to this so sorry if I'm doing things a little oddly!

I moved overseas from South Africa to the Netherlands in July 2019.

In March of this year I lost my French teacher in SA. I adored French at my old high school. I didn't know how to process it because I didn't get to say goodbye, and because I'm not used to too many losses in my life.

Then, last week Sunday, I got the news that an extremely close family friend of ours had passed away at just 70 years old - also living in SA. This took a heavy toll on me because although I have processed the previous death, this one hit me just as hard (if not worse).

Then two days ago I was informed that my mother's close friend's son had passed away (he is the same age as me), and, although I didn't know him, I feel absolutely terrible for her as I know how much she loves her sons and this news comes just a week after I found out about our friend. I also was told before my Mom was and found it too difficult to tell her so I sat with this news for over 12 hours, not having anyone to talk to.

I now find myself worrying about every and any little thing and thinking "if I do something this way, something bad is going to happen" just because I am so used to bad things happening now, and I find myself having OCD-like habits.

Any help is appreciated when it comes to managing my emotions and controlling this anxiety that I have as it's become so debilitating recently and I just want to stop thinking about the past.