SebMurphy,
I would agree with what others said, but I would add one important point.
A mortal sin does not require that one desire to offend God. This idea is called the “Fundamental Option.” Some people have taught that for an act to be a mortal sin, a person must actually make a choice in it between God and the sin. In other words, they must consciously say to themselves, “I can either have God, or I can have X,” andd then choose X. This is not correct.
The reality is that a person must simply know that an act is gravely wrong and do it anyways. It doesn’t matter if they even so much as think of God in the process.
However, in your case, the issue of whether you want to offend God or not is actually very important, but for a different reason. I know what you are going through, because I was once extremely scrupulous. I thought constantly about my actions and about the fact that they would offend God all the time. The reason that matters is that when a person truly fears offending God so much that they think of it constantly like that, it is almost impossible for them to actually sin without really, truly knowing it. There will rarely be any doubt at all if the person has actually sinned.
A scrupulous person - or at least many, and from your posts you seem to fall into this category - thinks about how an act or a thought might offend God whenever such a thought comes across his mind or when he thinks of doing some action. Because of this, for the person to consent, he will actually end up having to say to himself, “this act offends God but I am going to do it anyways.”
I used to have terrible thoughts going through my mind constantly, literally about 4-6 every 60 seconds at times. It was terrible. I was in constant fear I had offended God by these thoughts, and I spent virtually all of my time constantly begging God for forgiveness. I could not get through an Our Father without apologizing to God about 15 times. The reality of the situation was, every time such a thought went through my mind, I hated it, because I knew it offended God. I never decided it was ok to have the thoughts in my mind. I wanted them gone because of their offense of God. In order for me to have actually consented to those thoughts, I would have either had to say that I didn’t care it offended God - I would think it anyways - or I would have had to have stopped thinking about how the thoughts offended Him, which I never did, as evidenced by the fact tthat I constantly begged Him for mercy.
I wonder if anything in my story is familiar to you. If so, great! Not really great, but you know what I mean… great - it may be of help to you.
Let me very concisely make the main point here again:
If you desire to not offend God in such a way that you think about how something might offend Him when you do it, and you choose against doing it on that basis, then even if some part of you still goes ahead and does it, you cannot possibly be offending God.
Now obviously this does not hold true for very… active actions. For instance, if you choose not to masturbate but “some part of you” ends up doing it anyways, you have sinned. Masturbation is a very direct, active thing to do that requires you to actually consent to it in a very explicit way. In other words, its not like a thought that crosses through your mind, or even like a word that might slip out of your mouth almost against your will.
For these, I highly recommend Father Groeschel’s advice, as it helped me a great deal:
Deliberate consent means you have the time to recognize that something is immoral, and you choose to do it anyways.
It sounds to me like you can receive the Lord in the Eucharist. Feel free to PM me if you would like to discuss this more privately or explicitly.
Peace and God bless