feel out of my depth

I'm 6 months in post qualifying as a paramedic (UK), So far I've been okay and been lucky in the fact I've had fairly stable patients with nothing tooo scary bar a few poorly ones thrown in every other week.

The last two shifts I've had big sick patients and been on jobs where I've been the only paramedic with no back up and crew mates are either brand spanking new or just not clinical (they just drive and occasionally put on a BP cuff)

Felt like I'd finally kind of got the hang of being responsible but then after the last few jobs felt as if I've done everything wrong, consultants/nurses moaning I've prealerted big sick when they're not (they are when I ring ahead I promise) and it's just really knocked my confidence. I've spoke with other paras about the jobs and they've said that I'll find my feet and things will click.

Not sure if just a bit overwhelmed having a run of so many big jobs or I'm having one of those days but I just feel completely out of my depth, doubting my decisions and just not knowing what I'm doing....

When does it get easier?!

I'm constantly reading things in my down time, making sure I'm up to date with guidelines but I am just not enjoying the job right now, any advice/reassurance appreciated

Edit for spelling mistakes etc