I've only read the first couple of pages, so sorry if things have moved along, but I have to go out in a minute and felt compelled to post!
OP, I don't think it's weird to call him BF or DP or to celebrate your 'anniversary' just because you're not married. Anniversary is the yearly celebration of a special date - it doesn't have to be a wedding. We all have different relationships and how we refer to our loved ones is nobody else's business.
As a 40 year old calling my partner my boyfriend feels weird, but then partner sounds too official and we don't live together so I don't know what the MN acronym police expect people like us to do!
Anyway, DP and I are about to celebrate our 3rd anniversary. We won't be able to get married for several years due to each having our own homes and DCs whom we don't want to uproot, so for us the date we met is a significant one and will continue to be until we are actually in a position to get married at some point in the distant future.
However, having children, we can't always get the exact day free. I only get one child free night per week and he has his DCs 50/50 so the chances of our nights off colliding are slim!
I am unable to celebrate on our actual anniversary this year so we will go out the night before. We don't need to buy each other presents, but might just get a little token something. It doesn't have to be a big all-singing all-dancing weekend away, it's just a night out to mark the date we remember as being very special.
FWIW my ex didn't do special occasions either, he thought it was all a big cynical marketing con by Hallmark etc. The only cynical thing was his attitude. It doesn't need to cost lots of money to say I love you, but taking the time to acknowledge that your relationship is special means a lot. We all have different languages of love, for some people it is verbal, for some it is about loving touch, for others romantic gestures or gifts etc that show your partner was thinking about you. Just because some people don't need those things to feel loved, your need to celebrate this date is no less valid.
You need to talk to your DP, stating that you are disappointed but you realise that the conflict over dates is also tricky for him, tell him that you'd really like to do something to celebrate and maybe book the hot tub cabin as a gift and you can go another weekend?
Otherwise, just enjoy whatever celebration you are able to make time for. Finding someone you connect with is a real gift and some people may have taken this for granted a bit with their posts. When you have been in an awful relationship it is not unreasonable to want to make a fuss once you're in a great one!