What is the past tense of leventarme?

It's levAntarme with an A.

After DESPUÉS DE or ANTES DE you use the infinitive no matter if it's with any tense.

Examples:

Yo como (present) fruta ANTES DE levantarme. I eat fruit before getting up (when still in bed)

Yo como (present) fruta DESPUÉS DE levantarme. I eat fruit after getting up.

Yo comí fruta ANTES DE levantarme ayer. (past)

Yo comí fruta DESPUÉS DE levantarme ayer. ( past)

Yo comeré fruta ANTES DE levantarme mañana. (future)

Yo comeré fruta DESPUÉS DE levantarme mañana. (future)

and all the other tenses.

---------------------------------------------

Well, you got the infinitive "wrong". It should be "levantarse". Let me give you a few conjugations in some of the past tenses of "levantarse".

The imperfect conjucation of "levantarse" is

me levantaba

te levantabas

se levantaba

nos levantabamos

vos levantabaste

se levantaban

The preterite conjugation of "levantarse" is

me levante

te levantaste

se levanto

nos levantamos

vos levantais

se levantaron

Note: be sure to put an accent on the last "e" of the 1st person of the preterite, and accent the "o" in the 3rd person of the preterite (1st and 3rd person singular--but not 1st and 3rd person plural).

The subjunctive past conjugation of "levantarse" is

me levantara

te levantaras

se levantara

nos levantaremos

vos levantarais

se levantaran

This will help you clear up how some of the past tenses of "levantarse" are constructed.