freaking out a bit

ok, just need to panic

so i just looked at the website for the Tri i haven't signed up for yet, and lo and behold, the swim is not 400 meters, it's 1000 meters and then i looked at the finish times for last year, and
they look FAST
like i might finish last kind of fast.
I don't want to finish last.
I just want to do it. i think.

crisis mode.

am i too out of shape? am i setting my self up for major failure? is it worth it? am i cheating myself? I keep talking about it to people, and i'm excited about the idea of the tri, but horrified at the idea sucking. or not finishing, or even starting. am i ready? will I be ready? am I cheating the people that train all the time?
am I over reacting?
can I swim 1000 meters in under the last time from last year 36 minutes. Can I really swim for 1000 meters and then bike AND THEN RUN!

should i give up and face facts that I'm a terrible athlete? should I train like a crazy person, follow the plan, and try to tri? should I just work my way into races, like maybe do a 5 or 10k this year, and stick with the training plan? maybe August 5 is too soon... maybe I should look for one later in the year, to give me more time?
maybe you just have to start somewhere, and this is it. maybe I should just shut up and go swim 1000, and see how long it takes? how different is 1000 meters in the pool vs 1000 meters in a lake/pond?
AAAAAAGGGGHHHH

ok, freaking out more than a bit.