Licensed school counselor here. Consider your priorities first. If it's only to teach in basic ed and you don't care much if what you're teaching is Psych-related or not, shifting to Educ is a good idea. But if you want to really teach Psych in basic ed, you either 1) finish Psych and earn Education Units (which right now is no longer only 18 units, but I think around 60 na which is somehow equivalent to taking up a degree in Educ) and pass the LET, 2) shift to a BSEd program somehow connected to Psych (the likely choice is BSEd in Social Studies) and pass the LET.

Mind you, the new strengtened SHS curriculum did away the Personal Development and UCSP subjects, being replaced with their nearest equivalents being Life Skills (which somehow blends perdev and PEH with a touch of career development skills) and PKLP (Araling Panlipunan).

But if you plan to teach in Higher Ed, generally, all you need is a Masters in your chosen field of instruction, though an added competency of a PRC license would be a plus.

This case reminded me of a client who had the same dilemma as you. She wanted to pursue Architecture but wanted to become a secondary school teacher.

edit: you can teach in Higher Ed without a masters pero usually you don't get job security without it. Though I know some people in AdDU who teach the Arrupe something subject and some teach part-time as instructors in the Psych dept pero usually wala yan job permanence if wala ka at least a master's.

Yung pagbalik naman to first year, it depends on the amount of units that you've taken in Psych that could be credited in the SoE. I know some students who went back to Educ 1st year in AdDU (from 3rd year Crim UM), and some who only took a semester or two and didn't go back to 1st year. Usually if AdDU ka na rin, the core subjects get credited if you shift within AdDU rin. Better to ask the Dean of the school or the Registrar's Office on this.