If you find yourself longing for life away from your spouse I encourage you to share those feelings with your spouse. It may not be the most comfortable discussion you will have but, your spouse has a right to know that you are questioning whether or not you wish to be married.
If the negative outweighs the good in your marriage, your marriage is in trouble and in need of help. If there is more trouble than paradise, you need to get help in learning how to confront the issues causing the problems in the marriage. Problems feed on inactivity. Not taking pro-active steps to solve marital problems will lead to other problems and it only makes sense that the bad would soon outweigh the good in your marriage.
Do yourself, your spouse and your marriage a favor and don't allow the scales tip too far to the bad before seeking help and guidance in how to deal with those negative marital issues.
If either of you are overly defensive, dismissive of the other's feelings, show contempt for the other's beliefs or engaging in stonewalling tactics you are at high risk for divorce. When conflict is avoided or negative defense mechanisms are engaged when trying to deal with conflict you are not allowing healthy conflict resolution. It can be the kiss of death for a marriage.
Are you frustrated because every time you try to discuss marital problems your spouse pulls away from you? Maybe you have tried to express that you no longer care and you are the one distancing themselves from the marriage. It isn't uncommon for either spouse to withdraw if they feel the issues in the marriage are being avoided by the other spouse. Eventually one or the other spouse will shut down all together and no longer be interested in solving the marital problems.
Avoiding a major marital issue such as a lack of sex causes a marriage to die on the vine, it breeds resentment in the spouse who is feeling less than satisfied and it breaks that bond that all marriages should be built on...the intimacy bond.