Since grace of God is so great. then can we continue to sin then?

No:)

I reviewed my devos and notes and have these thoughts

There is no doubt that in Christ we have infinite forgiveness for every sin, Jesus did it on the cross to forgive our sins, once and for all. He did so "according to the riches of His grace, which He lavished upon you"-- Eph 1:8

" In Him we have redemption through his blood, the forgiveness of sins, in accordance with the riches of God's grace that he lavished on us with all wisdom and understanding. And he made known to us the mystery of his will according to his good pleasure, which he purposed in Christ, to be put into effect when the times will have reached their fulfillment-- to bring all things in heaven and on earth together under one head, even Christ"  ( Eph 1:7-10)

We cannot sin beyond God's grace, because where sin abounds, grace super-abounds 

" but where sin increased, grace increased all the more, so that just as sin reigned in death, so also grace might reign through righteousness to bring eternal life through Jesus Christ our Lord" ( Rom. 5:20)

You are forgiven for every sin--past, present, and future, You will never be condemned by God or seperated from Him ( Rom. 8:1-2,31-39)

However, many might ask, if God's grace is that great, can we continue to sin then?

In 2 Tim,  it is said that 

" Everyone who confesses the name of Lord must turn from wickedness" ( 2 Tim 19)

and God called us to to live a Holy life-- "not because what we have done but becuase of his own purpose and grace. " ( 2 Tim 8)

There are only two kind of slaves in this world, slave to sin or slave to God. 

" But now that you have been set free from sin and have become slaves to God, the benefit you reap leads to holiness, and the result is eternal life. For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord. ( Rom 6:22-23)

Roman 6:15