Wa alaykum salam,
In my opinion, this is a matter of the heart-- not of fiqh. In other words, what does your heart say when you miss a prayer or multiple prayers? if there's remorse, be glad, because that's a sign of faith. Allah azza wa jal made us with a conscience. I was just reading through surah 2 the other day and was amazed. Despite the numerous backslidings of the jews, He forgave those who earnestly repented. Some of their hearts were as hard as rocks, while others were like rivers gushing out of rocks, as it were (see surah 2:74).
I don't know where your heart is, but even if it is like a rock, there is still hope, but you have to go on God's terms. Muslims can struggle with sin, but there's no such thing as a habitually carnal muslim.