Firstly: 

There is no doubt that the husband who goes away from his wife because of study or work and lives in a land far away from her is exposing himself and his wife to temptation and sins that have to do, in particular, with the gaze and the private parts. Hence we advise husbands to pay attention to this important matter and not stay away from the marital home so that they will not expose themselves and their wives to temptation that may lead to losses in both spiritual and worldly terms. 

It is no secret to the Muslim that looking at indecent websites is haraam (impermissible) and causes damage to one’s spiritual well-being and religious commitment. We have discussed the ruling on this and ways to rid oneself of this in several answers. Please see the answers to questions no. 12301, 39923, 26985, 10459 and 7669 

Allah, may He be exalted, has commanded men and women alike to lower their gaze. Being away from his wife does not give the husband an excuse to look at things that are forbidden to him, otherwise that would also be an excuse for his wife! And this is not something that Allah has prescribed. See the answer to question no. 20229, in which we have mentioned twenty-seven ways to help one lower one’s gaze. You will also find the benefits of lowering the gaze in the answer to question no. 22917. In the answer to question no. 33651, we have mentioned some ways of dealing with the fitnah (trial) of women. In the answer to question no. 20161 you will find a solution to the problem of desire and how to fulfil it. 

With regard to the secret habit, it is also haraam. For more information on the ruling on masturbation and how to deal with this problem, see the answer to questions no. 329 and 101539 

Please note that your kind treatment of your mother will not excuse you for these sins; rather honouring your mother is a great good deed, but what you are falling into ara bad deeds. And all that will matter on the Day of Resurrection are good deeds and bad deeds, so beware lest you destroy what you are doing of good deeds and lose out on the reward for them because of what you are doing of bad deeds, if they accumulate and outweigh the good deeds. 

Secondly: 

What we advise you to do is one of the following things: 

1.

Go back to your country and stay with your mother and your wife, even if this means earning less money and having less. If a person gives up something for the sake of Allah, Allah will compensate him with something better than it. 

2.

Bring your wife and your mother to live with you in the country in which you are working, if you are able to do so. 

And Allah knows best.