What are my options for staying in Thailand until May 2023 after facing entry issues?

German Passport holder here (35years old/early retired because of health problems), staying in Bangkok.

I arrived on 18.Nov 2022 with a 60 day tourist E-visa and planing to stay in Thailand till middle of may 2023(depature flight already booked).

When i arrived in BKK, i had problems entering, because i stay in thailand to often and too long and the immigration officer told me, i need to book a flight out of thailand in 60 days, which i did at the airport, after i could enter.

They told me, that i´m not a tourist and that i will have problems again, when i arrive to thailand next time. They said i have to marry my girlfriend (she has been in germany 3 times already), if i want to stay in thailand for longer periods of time.

In all the years i come here, i never had 1 day overstay or any problems with police or immigration. I always obey the immigration rules, only did two visa runs in 2016/2017. I don´t work in thailand, i get retirement pension and live off savings. I´m living with my thai girlfriend together.

All that, i also told the immigration officer at BKK airport.

My passport is full of stamps from different countries, because i travel a lot.

I will extend my 60 day e visa for 30 days in january and in february i´m planing to do a 2 week vacation in some other SOA country with my girlfriend together. After the 2 weeks we will come back to thailand and i´m scared now, that they don´t let me enter.

What are my options? i need to stay in thailand till middle of may, because my family will come for visit in april and they already booked their vacation.

I will likely enter Thailand after my 2 week vacation through BKK airport. Is it better if i use VIP service there, so i won´t have problems at immigration? Or should i book an extra flight after my arrival, from BKK to some other airport in Thailand and enter there into the country?

One other option would be, that i do 2 borderruns to cambodia, one in february and one in late march (to get the 45 days visa on arrival). But the immigration officer told me, that i shouldn´t do any borderruns, because this will lead to more problems when i arrive next time to thailand via plane (i´m planing to make a new passport anyway when i´m back to germany, because this one i´m using is almost full).

here is my travel history from the last "2 years" in thailand:

arrival feb 2021 depature august 2021 (5 month) (2 or 3 covid extension stamps)

arrival march 2022 depature june 2022 (3 month)

arrival nov 2022 depature xxx (feb 2023) (1,5 month + 1,5month in 2023)

So what is the best option for me, that i won´t have any problems entering thailand again in march and continue my stay till may 2023? (my girlfriend will be traveling with me. it helped before, that she could talk with the immigration officers in thai, because they don´t believe me, that i´m retired, even i showed them proof of it).

Thanks already for the help.