I'm glad you enjoyed it!
Practicing lovingkindness on yourself is incredibly hard. I read somewhere (Jon Kabat-Zinn I believe) that you should imagine a baby, kitten, or something innocent you can love easily and unconditionally. After a while sitting and thinking of that feeling, turning that same feeling of love towards yourself. It's incredibly hard, and can bring up some painful feelings. I remember it physically hurting the first time I did this. But with time it gets easier and you can learn to be less critical of yourself. Good luck on your journey!