It seems there is a difference.

Incel is involuntary celibate, a guy who wants sex so much that he sees it as the ultimate goal in life, yet he cant have it. Normally his obsession comes from scarcity and the fact he was rejected several times. Although the incel is primarily focused on sex, the incel problematic is often accompanied with a bit of TFL, because he worships and idealized archetype of female so much he idealizes the sex being given to him just for who he is, this makes him a beta. If he really only wanted sex and he didnt care what others think he would get whores.

A TFL is a guy who's first priority is to have a girlfriend and a relationship, of course he wants sex but he idealizes women companionship, to toxic and unrealitic levels. This prevents him from seeing the reality that being alone is good, and ideal. The TFL guy sometimes lacks good male role models and good male companionship, as the incel too. But he tends to underestimate his own life, or lack life goals and hobbies. The tfl solution is just finding your own hobbies and what to stand for in life. A few male friends with the same purpose as you are far more important than an harem of women.

Both tfl and incel are modern problems, created by bluepill illusions.