Do you mean Confession? Or some sort of “general absolution”?
I am under the impression that a very few holy individuals who joined the cross in a very close way will depart this life and immediately enter into heaven. Most of us, if we are saved, will most probably have to spend some time in purgatory.
The issue at stake with confession and absolution of mortal sins is not purgatory, but the loss of salvation. Unconfessed mortal sins must be confessed.
Now, God does not ask the impossible, and He also is omniscent. What He requires of us when we commit the kind of sin that is mortal and brakes communion with Christ, is that we experience contrition (or at least attrition) and have the firm intention to confess as soon as possible.
The Church also teaches that perfect contrition (that is to say, repentance due to the sorrow of having offended God, who is all good and deserving of all our love, rather than due to fear of hell or of material loss) united with the firm intention of confessing as soon as possible, can obtain from God even the remission of mortal sins. If one were to - God forbid - pass away under such a circumstance, Christ would take into account the penitent’s repentance and his firm resolution to confess as soon as possible. If the heat of the day is a sincere concern due to health reasons of any kind, then definitely the prudential thing would seem to confess on the next most suitable occasion. If the heat is a mere disturbance that would not threaten our health, it may be worthy to offer the sacrifice and bear with it for the sake of confession.
HOWEVER…you said that “as you were thinking, the bus went by and you missed it”. It was not your fault. You did not decide “I will not go” (which might even have been the best decision). You merely suffered the consequence of an accident: you missed the bus. The matter was no longer in your hands at that point, and was to be accepted with resignation and trust in Christ. If He could bear the terrible torments of the Passion out of love for your soul, do you think He won’t pave the way and send His holy angels in order to cleanse your soul of all sin before He summons you to the House of the Father??
The Lord is very understanding but requires that we do all we can in order to comply with the precepts - that is to say, the commands - of Holy Church, such as attending Holy Mass on Sunday and Holy Days of Obligation. If your personal situation - which you need not disclose - prevents you from arriving to Church in any other way and there is no bus on Sunday, then again, God does not ask the impossible of us! However it is important to mention this to your pastor and have a dispensation, which you say you did.
Having an intuition of how supernaturally important is to attend Mass on the Lord’s Day and Holy Days of Obligation (or the Vigil Mass the previous evening), I encourage you to “keep knocking” and try to find an “angel” who may be willing to accompany you at least on some occasions. Maybe it can be mentioned on a bulletin, or in an anouncement, or something?
In any case, may the Lord who inflames your soul of love for the Eucharist bless you and keep you in His peace. I want to bring a very insightful article to your attention. It concerns the sort of trust and serenity we ought to have when we strive to live with a penitent heart and recur to the Sacraments as often as needed and as often as possible.
How long have I waited
People should experience that you recognize that you are a sinner and joyful, because you do penance knowing that God forgives. There is no sin that is too big for God to forgive. The only sin that He cannot forgive is despair, when we stop believing that he can forgive or we begin to believe that he is so angry with us that he won’t forgive us even if we asked.
If we make regular use of the Sacrament of Reconciliation, we don’t have to worry about being forgiven. We can walk through a crowd with serenity, because we know that even if everything else collapses around us, we will not collapse. We are held up by the grace of God that we receive in the sacraments.