Have you tried like deep breathing? In through your nose for like 2 seconds, out your mouth over like 2 seconds. I also sit with my legs crossed, back straight and 1 hand on my stomach. If you can, do it in a place you like/find peaceful and relaxing. If not your living room floor works. For me i live next to the ocean and have lived by it my whole life so im kinda at home in/around it and the sound of the waves and the sea breeze on my face is very relaxing. So i do it there. But a park, lake, hike trail etc could all work. And generally just having time for you and taking care of yourself, doing things you enjoy can help if you're not already.

Years ago when i was 20 or so i guess i had my first/only? anxiety attack, that lasted a week. Chest pains or whatever, a pain that went down my left arm, chest having an intense buring sensation and warm to touch (to the point i rubbed icecubes all over my chest, shoulders and back) and other stuff i dont remember now. Needless to say i was freaking the fuck out for that week, constantly considered going ER, ended up going into the doctors office past normal hours, stating my symptoms. I think i caused a panic in there, especially with the new/young nurse girl. Had all sorts of tests done, 2 doctors look at me. Everything came back great and they said they thought it was anxiety/tons of stress. I left feeling like i had wasted their time.

Anyway, i started the breathing thing and it helped a ton. Did it every night for months after this experience. Now a days not so often but still do it from time to time.