The first thing you need to do is figure out what the heck is going on. As soon as you do that then you can figure out how to fix it. What do the two of you fight about all the time? Money? Money is the number one reason people fight and marriages end.
When you first meet and are falling in love, everything is wonderful. It seems as if the two of you were made for each other and you decide to get married. After the wedding you try to combine your lives into one and unless you both learn to compromise, this is where resentments and misunderstandings can start to creep in.
Then what happens? Life comes front and center and instead of spending all your time together just being in love, you have to deal with work, the bills, the kids, the house and the yard and all of a sudden there is no time for the two of you. You barely kiss goodnight before falling into a fitful sleep that does nothing to relieve the exhaustion that you feel.
Some ways to save a marriage include making time for the two of you at least once a week. Plan a date night every week and do not let anything get in the way. Ask grandma and grandpa to watch the kids and go to dinner and a movie or spend the night in a hotel room and just reconnect. Order room service and have your dinner in bed. Leave the TV off and only call once to check in with the kids, then turn the phone off. Get a real good dose of each other so when you have to face reality again the next day you will be fortified against the world and it's perils.
If money is a real problem, figure out how to bring more money in or figure out how to spend less. Cut out unnecessary items and buy only what you need. As soon as you get your feet back underneath you the sooner you can relax and stop worrying about money all the time. Try to stay positive and positive things will happen. Small changes can make big differences in your day to day lives.
If you find that these things are still ineffective then by all means see a counselor. The love you have for each other is worth it and a good counselor can shed some new light on your relationship and help you breathe new life into it. Seeing a counselor can be one of the ways to save a marriage.