I really don't like the flop raise. What you're effectively doing is turning your hand into a bluff, because pocket eights is probably pretty close to the exact cutoff point where he would never call your raise with a worse hand, but he would never fold a better hand. There should be a name for this exact cutoff hand, but I can't think of one yet. I'll coin the phrase when I can think of something.

If you're putting the UTG raiser on two big cards – which is far too specific a range to begin with, because you acknowledged in your explanation of your raise that it's a possibility he also has a bigger pair than yours – then there's no reason at all to raise, besides being scared of seeing a turn card, which is not a valid reason. If he has two big cards, he has six outs – the rest of the time, when those six outs don't hit the turn (six outs x one card = roughly 12% of the time) you still have the best hand. All you're doing by raising is getting him to fold all his weaker hands that might have put in further bets on later streets, and valuecutting yourself against stronger hands.

In essence, your reasoning is backwards. You have a pretty good hand, 88 on a 224 flop. Why would you want to take an action that a) prevents you from getting value from his worse hands, and b) loses you more chips against his better hands? A better approach to take would have been to put the villain on a range preflop, and then again on the flop, and make a flop decision based on your assessment of that range. To me, it seems that the obvious flop play is to call and see a turn card – some turns you can call again, some turns you can fold. You're probably doing okay against his range right now if it contains a lot of 'big card' hands, but you're also crushed by all the bigger pairs. Don't be scared to call and see another street with a middling hand like this – overplaying it, as I believe you did, could cost you more chips.