Congrats Sara for the start and finish. A question... did you try to rejoin the pack when the lapped you? The Exergy 2012 is a pro team lead by Kristen Armstrong. It was formerly Peanut Butter and Company 2012. The 2012 derived from the next Olympic year with several of the women trying for the Olympics. The other women were the usual suspects in a P/1/2 field. The promoter opened it up for all categories but did not do the Cat 3/4 any favors - technical challenging course, pro field, fast pace. Beginners will not learn much in a race like this.
In this type of field the racers know and mark each other. If you were on a wheel, that one of the stronger women thought was hers, you were going to get shoved off. You have no track record racing with this group. So this would compound your problems of holding wheels and position. There was no way they would allow you at the front.
Learning and strength increases occur when you mix it up in the pack for long periods of time. Since you like crit racing, you need to find races for cat4 women only with mentors on a simple four cornered course with no grades or local practice crits. In this type of race, the women are going to play nice and you can learn to corner and get exposed to the accelerations which will improve your fitness. Riding a course by yourself even motivated by a field lapping you is not great for fitness per se. I have done it. Sometimes I thought I should be on my TT bike so at least I can get a good TT workout in.
I am glad you are not discouraged. You were in a cat fight with a bunch of cougars and you were a kitten.