Lack of pleasure during sex can be due to many reasons. It doesn’t seem that frigidity is the reason for your displeasure because you like sex and enjoy masturbating. Lack of orgasm and sexual pleasure is a different sexual disorder than frigidity. Some statistics state that only 30% of sexually active women reach orgasm during the sex. Another 40% will reach the orgasm if the clitoris is stimulated during the sex. 20% can achieve orgasm only with self-satisfaction (masturbation) - you might belong here. 10% of women never achieve orgasm. The two most common reasons for lack of orgasm are not-enough sexual stimulation and psycho-emotional problems. A rare organic reason might be a large vaginal entrance and relaxed perineum where there is not enough clitoral stimulation during sex. Because you have tried many sexual techniques without success but you enjoy masturbation, you might be experiencing a mental block to satisfaction. You can consult a mental health doctor for a consultation, someone who has specialized in sexual disorders, like a sexologist.