No, you are **not **in mortal sin. The general principle of Church law is that no one can be obligated to do the impossible. Since you have no conceivable way to attend Mass, your obligation is abrogated.
When you pray you can make a spiritual communion:
Ecclesia de Eucharistia, #34:
In the Eucharist, “unlike any other sacrament, the mystery [of communion] is so perfect that it brings us to the heights of every good thing: Here is the ultimate goal of every human desire, because here we attain God and God joins himself to us in the most perfect union.” Precisely for this reason it is good to cultivate in our hearts a constant desire for the sacrament of the Eucharist. This was the origin of the practice of “spiritual communion,” which has happily been established in the Church for centuries and recommended by saints who were masters of the spiritual life. St. Teresa of Jesus wrote: “When you do not receive communion and you do not attend Mass, you can make a spiritual communion, which is a most beneficial practice; by it the love of God will be greatly impressed on you."
A popular prayer of spiritual communion is:
My Jesus, I believe that You are present in the Blessed Sacrament.
I love You above all things and I desire You in my soul.
Since I cannot now receive You sacramentally, come at least spiritually into my heart.
As though You were already there, I embrace You and unite myself to You;
permit not that I should ever be separated from You.