Been divorced twice. It is never easy or fun even if it is for the best. It takes both of you wanting it to work or it just won't no matter what. You don't have to be on the same page all the time, but you do need to be in the same book at least. You both need to sit down together and separately and get your feelings, needs, and wants figured out. You each have to know what your own needs are before you can hope the other person can meet them. And no one person can meet all your needs. First you must understand before you expect to be understood. You both need to go to the trouble to write down this stuff. Your goals individually and your goals for the marriage. What you bring to the table and what you want the other person to bring to the table. What things are deal breakers and what things are just minor irritations. You may find out you have very little in common when it comes to these things and you may find you are both pretty much in tune. Things like kids, religion, finances are the biggest things you both have to be very close to the same on. For example, if you are a saver and she likes to splurge, there WILL be problems without both of you making big adjustments. Marriage takes regular maintenance just like your truck does. Sometimes it needs minor repairs, sometimes major overhauls. Sometimes it is too far gone to save. Most of the time however unless there is some form of abuse going on, whether substance (or any other addiction), physical, verbal, emotional, or sexual, things can be worked out. Neither party can give all and neither party can take all. Balance is required. Both of you have to be able to lead or follow as the situation demands. Strive for an equal partnership even if one of you makes the bulk of the money or does the bulk of the housework. Marriage means two people becoming one couple. Each with an independent identity. You are an individual, she is an individual and your marriage is an individual. Each with specific needs and each with different levels of maintenance required to keep it running correctly.
You are in charge of your own happiness, not someone else. Your thoughts, feelings, goals, etc are YOURS. Nobody else can create them. You do. You have the option. If you aren't happy, it's your fault. Someone else may have done something that you didn't like, but it is up to you to control how you react to it and what emotion you use with that reaction. Everybody hears "Oh he (or she) makes me so happy" Bullbleep. People get so caught up in that kind of thinking they don't even bother to develop their own emotions nor do they learn to use them correctly. Someone can provide an opportunity for you to show happiness, but they didn't make you happy nor do they make you sad. This does not mean you will be giddy at your mother's funeral just because you can choose to be. It does not mean you won't ever be sad. It means you are in control of how you feel. Pain is temporary and unavoidable. Suffering is lasting because it is self-imposed.
Good luck to both of you.