Welcome to the Beyond Blue forums and thank you for reaching out for support and advice.
"Do you think he has abandoned the family and being selfish or am I being
stubborn not to go back with him to give the kids a complete family
This may not be easy to give a 'yes' or 'no' as I feel there are many layers building to this outcome.
"Unfortunately he decided his career was not doing well therefore
decided to move back but due to my career thriving here I was reluctant
to come back with him and he has not persisted that I should come back
For instance, what was the conversation surrounding his decision while
knowing that you were happy and doing well in your career while his
status was diminished by lesser success? Up to this point, was the relationship on a sound footing?
His return may have been prompted by your success in a bid to remove this power from you since your reluctance to move - in a way, he may have exploited your preference to his advantage. In this case, it is sad you could not receive the support from your husband but instead find a level of emotional/financial blackmail to force an outcome in his favour. If not for you personally, your husband should still show willingness to provide for the children who are the innocent victims undeserving of such treatment and I also feel sorry for them that their father has effectively abandoned them (- a weekly phone call is not adequate parenting).
So perhaps there is a mutual stand off awaiting one or the other to weaken - a battle of wills, where the one to concede will feel worse. Have you discussed separation (officially) with your husband? This may clear a path to finding a resolution (both good and bad) as I think you may be in a stalemate with you being more on the losing end.
Regarding future relationships, joining social groups (culturally focused) and becoming familiar with a strong support network can avoid any unpleasant surprises - not need to dive in before testing the waters...