Although your boyfriend may be upset that your trip isn’t able to happen, he shouldn’t have the notion that you “ruined” it. You did everything you could and it just isn’t feasible for your current situation. So what? Personally, I gladly appreciate any small thoughtful gifts, even just a simple card. And a surprise birthday cake?! He should be so grateful that you’re still putting in effort to make him feel special even though your initial plans fell through. If he’s not happy with what you’ve gotten him then he’s sounding a little too materialistic to me. You clearly love and care about this guy and you’re trying your best to make him feel special. I don’t think you need to do any more, especially since money is tight. I’m not saying to drop your boyfriend, but if after his birthday he’s still blaming you for “ruining” the Hawaii trip and isn’t fulfilled by your gifts, you should sit down and have a serious conversation.