My friends and I are going in 18 days (end of August) all 3 of us are fully vaccinated in our 20s. We got N95 masks to wear in any type of crowds, and surgical masks as well. We thought about canceling, but just couldn't justify losing the tickets (my friends are former cast members, and the comp tickets they had gotten to keep expire in September.) We are planning to avoid rope drop crowds and stay later at the parks instead, and we are DVC so will be doing a certain amount of meals cooked in our own space. I'm still a little nervous, however these groups have helped me feel more prepared.
Dont be nervous, if you got the jabs and wear a mask, the chances of having a breakthrough infection is low, and extremely low to get hospitalized; just go and have fun