Getting into it??

So when it comes to masturbation i can never get into the mood. No matter what i try:/ and believe me i’ve tried a lot

my bf has fingered me and it’s better than when i do it but i feel a little bit of burning around the entrance but not anything to make me not like what’s happening.

i’m also worried about the taste, when i try anything myself i get a acid or a sour ish taste, but nothing super bad i just that’s not what my boyfriend tastes. i drink so much water it’s crazy (2-4 liters) advice??