Struggling w/ Reintegration of Spouse

I am a former USMC service member with zero deployment history while spouse has served in different capacities in the Army & National Guard for 15 years. We have been together for 9 yrs and spouse has just returned from a non-combat deployment. My mental health has taken a major hit in the last four months and upon spouse’s return. Things are different and I keep feeling like it’s all my fault (some stuff went down while spouse was away). Spouse and I are struggling to reconnect, but I want to so badly. I was hoping I might find some support or advice here? This is uncharted territory for me and I don’t know how I should be reacting. But I am struggling so hard. :( I don’t even know what to ask for or where to start with any of this.