Advice for the lovelorn
On the subject of whether ENFP and INFJ are a good match in typological terms:
A lot of us current members on this MBTI-C message board came over here from INTP-Central, where an INTP/INFJ match is considered a pretty solid one (two laid-back types giving each other a lot of space). IOW, a lot of us may have a bias in favor of matches of certain types of similarity (Introvert/Introvert matches for example). As for myself in particular, being in an INFP/INFP relationship, I can hardly disagree.
OTOH, there are some traditional MBTI experts who believe in matches of complementarity (Introvert/Extravert matches for example). In at least one or two cases they especially distinguish the INFJ as the most purely avoidant of the types and recommend that INFJs pair up with a rambunctious Extravert in order to learn how to get out of their shells. By the same token, I can imagine that an ENFP would benefit from a relationship with an INFJ, in that ENFPs could benefit from learning some of that INFJ gravitas and reserve.
So who knows. Clearly Jake is into his girlfriend, and clearly his girlfriend was interested in him at least for a time. The match may not be made in heaven, but it might be a good one for each of them in particular.
As for where Jake goes from here:
The girlfriend is in full flight for the moment, and the strength, height, and blankness of the walls she has put in Jake's path makes the prognosis seem pretty bleak. OTOH, I've played this game a few times in the past, and I see a couple bright spots:
1) The girlfriend was clearly and strongly into the relationship for a time. That's a important positive, because one lover's spat shouldn't normally be enough to cancel that kind of longer-term interest.
2) Some of Jake's belongings are still at the girlfriend's place. She hasn't boxed them and dropped them off at his place or told him to come over and clear out his crap. I don't tend to be into traditional relationship gamesmanship myself, but in traditional relationship gamesmanship the existence of belongings at each other's place is considered a lifeline keeping the relationship alive. Return of someone's belongings is considered the cutting of an important lifeline.
3) Jake's slip-up consisted of using the "L" word too quickly and perhaps pressing for sex too quickly. In my experience with avoidant types, that error tends to get you a 15-yard penalty but doesn't get you thrown out of the game. Women usually don't come to hate a man simply because he loves her. Instead, they mainly just want to enforce the concept that they get some say in the timing.
I've been in relationships with a couple strongly-avoidant types in the past, and I've seen them play the game this way--abrupt, sharp cut-offs of contact. It seems like careless brinksmanship, but in the end I think it's all they know. They let problems build until they get so distressed that they hit the panic button. It doesn't necessarily mean that they're nuts. It just may meant that they need someone to help them a bit: Coax them back out of panic mode over the short-term, and then over the long-term help draw them out of their shells a bit and show them by example how to communicate better in other modes.
I don't want to speculate on Jake's chances with his girlfriend. I don't know the two of them, and they may still be quite young and dumb. In my own past love life, I've patched up much worse breaks than this one. Of course, even if the prognosis is good, Jake and his girlfriend could blow it by deciding to stay in their "safe zones" and choosing to jettison the current unfamiliar, scary, bumpy relationship with its unfamiliar playing rules.
But I hope they try again. If they've been together for a bit already and have developed a certain foundation of trust, then they can use that reserve of trust to step outside their safe zones and learn from each other. With time, hopefully they'll get past the crude stage of pushing clumsily on other's boundaries and then cutting each other each other off in a panic, and they'll learn more sophisticated ways of communicating their needs and differences.
I think Jake's doing the right thing: Leave her alone for a couple days--let her stew a bit by herself and simultaneously demonstrate to her that he understands she has boundaries and he's willing to respect them. Then subsequently show that he's confident enough and caring enough not to consider the time-out to be a deal-breaker. IOW, use the reserve of previous goodwill to buy some time for the relationship; grant her the right to use withdrawals and time-out as a personal safety zone for her; in return ask for her to be patient and not take offense at his clumsy pushiness and denseness about her boundaries; and then subsequently work together to learn each other's signals better and develop more sophisticated ways of communicating their needs to each other.
Again, I don't want to offer a prognosis or start doling out a lot of step-by-step advice. But on principle I think it's good to move outside one's safe zone in relationships and learn some new moves. Win or lose, that's the first step toward real maturity and self-confidence in relationships.