Bluffing is an art and needs to be done where it can make sense.
you say that you always get snap called by two pair, are you getting snap called by hands with only top pair or second pair hands? If not then it’s a bit unfortunate but I have a few tips.
Try to bluff on where you have an opportunity to draw out on your opponents (bluffing with straight or flush draws for instance) preferably drawing to the nuts or 2nd nuts. For instance, on a T64 rainbow board, C-betting with a hand like 78 suited is better than with AK. On straighty and flushy boards, such as 79Q with 2 diamonds or 678 rainbow betting with hands that will make straights or flush with a hand like JT (especially of diamonds) allow you get hands that have you beat like 2nd pair or two overs that have significant equity to fold.
Also, not all bluffs work. Sometimes your opponents will just have it, and that’s that. Just remember to check your bet-sizing and timings. If you only go all in on the turn with a bluff then people may pick up on that and just start calling you. It’s a discussion that requires more than just a post.