I enjoy both fucking and love-making.

I agree that there are long last effects after love making ends, but the same power that started it [lust] is still there. My sex life with my girlfriend is just as fun, dirty, sweaty and filthy as it has been with others that I didn't love.

Yep, it's sometimes a fuzzy line, but each intimate act is somewhere on that spectrum between the first and the latter of what you say, even with the same person, there is the short term immediate satisfaction (sometimes with remorse and embarrassment) and the more meaningful, memorable relationship sustaining acts.

We all have our comfort zones and self esteem deficiencies or surpluses that will usually dictate what we will allow or encourage or discourage for ourselves at any given time. That often changes over the years, and we shouldn't beat ourselves up for craving one or the other, but of course of the two, the love making is the more high quality and cherished event.

Sex is physical whereas making love is both physical and emotional.

IN my experience love making can be a damn good fuck, and fucking can be the beginning of a very loving relationship.
Never underestimate Lust.