Emotional triggers: how do you manage them?

Good morning lovely people 😊

My name is Amber, and I have experienced a few traumatic events over the last couple of years. The worst things happened in 2015 and 2020. I still have recurring flashbacks and nightmares from these events, mostly about the 2020 event, and I avoid anything that reminds me of what happened. I know this is bad and that eventually I will have to bite my teeth and work my way through this, but another part of me feels that I should just let it be, and let time do the healing...

I won't go into details but the hardest thing I had to do was to learn to trust my boyfriend again, since he is the one who broke my trust in the 2020 event. The good news is: we have made so much progress since we got back together, and he has not given me any reason any more not to trust him.
The 2020 event is almost 2 years in the past today, and most of the time I'm not consciously thinking any more about what happened 👍 but these TRIGGERS still come out of nowhere, and on a bad day they WILL throw me off balance ... My boyfriend tends to get upset about this, because he thinks I still don't trust him. And yes, it can ruin a perfectly good day for both of us 😔

The problem is: pretty much ANYTHING from that specific period of time in 2020 is a trigger to me: Pictures. Songs. Places. Dates! Names. Cars. Clothes. The ice cream truck jingle. It's all tattooed in my memory, like a warning sign.
Worst of all: my boyfriend's ex-girlfriend (the one he was seeing while we lived apart) keeps showing up in our neighborhood because she has friends living very close to us.
This is making my situation almost impossible to handle - how can I get over the past, when her presence keeps on triggering me, reminding me of everything I wish I could forget?

Whenever I get triggered, I'm getting so worked up, trying hard to act normal but I'm really struggling not to cry or fall apart. (I can hear my boyfriend asking: "why are you so uptight?")
Today, I got a notification from Google Photos to look back on a certain memory from 2 years ago. It shows a picture of my old apartment, where I was living during this difficult period of time, in 2020. I'm scared to look at it. I feel like I should just delete that picture. I already have deleted so many pictures of that year - even pictures of perfectly good moments! I just couldn't stand to be reminded of the bad things.

I also have sleeping issues: falling asleep is no problem, but I get woken up by the slightest sound or movement. I have very vivid dreams or nightmares sometimes, and I almost don't get any good quality deep sleep...
I have tried cutting out food or alcohol (the usual glass of wine, not more than that) before bedtime but it didn't help at all.

My biggest question is, and this is also why I joined 7 Cups: how you deal with these triggers? What are some grounding techniques that really work for you? How do you put your mind at ease?

Any tips are welcome. Thanks for being here today, and thanks for listening❤️

Love,
Amber