I am confused about the past necessitative. First of all, there seem to be two tense signs in the same word:

Gitmeliydim.

Do -meli- and -di- refer to the same situation or has one of them something to do with the truth of the situation? I mean is it translated

1. ´I had to go´ or

2. ´I must have gone´?

Both of them are possible.

Is it the same context as the -meli/-malı used for "gereklik"?  örn; inanmalısın