How likely is admission to clinical psych straight out of undergrad?

[honkhonkhonkhonkhonk]

I just started my fourth year of undergrad and started my thesis and I’m freaking out.

I know clinical psych is competitive and I just want to mentally gear up for the next application cycle. I don’t feel like I did “enough” in undergrad since the competition to get into these programs gets harder and harder each year. I’ve been a clinical research assistant involved in each stage of the research process at multiple different labs, got two co-authored publications, and multiple posters at conferences (some international). But I think imposter syndrome is kicking my butt right now. 

How do you guys prepare for applications, especially with reapplying year after year? How likely is it for someone to get an acceptance straight out of undergrad?