I survived Brendan's early 45 min napping ways (he started around 7 weeks), by focussing on helping him to learn how to fall asleep at the beginning of his nap (pat shush), if I could get him back down at the 45 min. mark (I would go in early, somewhat a wake to sleep method) then I would use some accidental parenting and lie down with him, take him out for a walk or car ride.
When he was 3 months old, then I changed methods. Since he was old enough to begin self soothing, then I tackled things differently, going in early, applying pressure ( he was a side sleeper) on his arm, legs to stop the jolts, shielding his eyes from visual distraction. And I stuck to it.. he would get upset and cry and cry because he was soo tired, but I just continued to help him resettle. As he progressed to 4 months, then I went into pu.pd.
A few things that helped-- a very dark room, making sure he fell asleep independently (assisted independently prior to 4 months), keeping awake times short (under 3 months) and ensuring overstimulation doesn't occur, and of course.. keeping myself calm! and just knowing that it's developmental and he will get through it.
Typically, infants go into a morning and afternoon nap pattern by 6 months of age, with consistent 1.5-2 hour naps. Some need more guidance, where you need to tweak habits and lenghten awake times (after 3 months of age.. NOT prior).
Hope this helps,