Is it just a girl thing to always think the worst or am I suffering from real anxiety?

Tee

So a year ago I lost my brother whom I was a career for for many many years. This has left a massive void in me because it felt like I lost my child. Since his death, I have become really panicky and anxious about losing people. My boyfriend sometimes disappears on me for a day or so (it used to be worse before) and then I start thinking the worst, like somethings happened to him on the way home on the motorway because he’s constantly fighting fatigue and driving can seriously hinder him. He’ll message me a day or so later and just tell me he’d been sleeping or got caught up etc which is fine but during the time he disappears and doesn’t get back to me my mind is doing overtime thinking the worst and keeping me up having panic attacks.

He’s done this a few times before and I’ve explained to him how anxious I get and he really does feel bad. But he’s done it again and I can’t tell if it’s just a girl thing where we as gf’s starting doing hospital checks because our bf doesn’t pick up one call or I’m actually suffering from anxiety? I don’t hound him, if message him and he won’t get back for 6+ hours which is odd so I’d ask him if everything’s alright and then radio silence, like he won’t be on his phone at all. Before he’d do it for 2+ days but he’s gotten better.