Its good to hear that you remain attracted to him and are trying your part to work things out with him but I get the impression you are already 90% decided to move on. 5 love languages is a good indicator to help know the other person better but its not definitive. It can help couples to understand each others preference and why the other partner does not express their love language in that way. A good couple will try to understand what the other person's key languages are and try to make an effort to display affection in that partner's language. I've noticed you have mentioned your love language being physical touch and his being on the low side. If I might ask what is his top 2 love languages then? It sounds like he is a words of affirmation or acts of service person since that is how he likes to retaliate in such a way. What do you think would make him happy? e.g. going to the movies, playing games (since you mentioned he is a gamer), a particular sport, drawing/painting etc.

Another thing to note is if things were already shaky at the 4 year mark why did he choose to propose to you? Did he also "settle" or was there something positive that he saw in you which pushed him to make the move or did he come across of being too afraid to lose you. If you are both always arguing on a holiday when this is suppose to the most fun/relaxing time that is a warning sign and could mean significant incompatbility issues. There is also a possibility your partner prefers a different type of holiday and is trying to accomodate you and the family.