Oh I can relate! I spent a good deal of time at white belt (because of work/travel/moving interruptions) and was promoted from 2 stripes on my white to Blue. Talk about a surprise and feeling like chum being thrown into the waters of the 4-stripe killers.
I simply started all over again with my goals and began with "don't get submitted. Didn't feel good to miss the medal round on my first tourney but I achieved that goal. Small steps and enjoy the grind.
I find Kimura to be the best one to start with personally because of the variety of positions you can catch it from, the dominance of 2 arms attacking 1, and the control you have while trying to adjust and finish.
Go gettem killer!