We can only answer if we know the full story and I feel that you have been vague. You have only given information where it suits you.
1. To own houses in Thailand (as opposed to condos) you have to be a Thai citizen with one or two exceptions. One being that you are employed in certain sectors required by Thailand (teachers and so forth). You cannot prove your employment, so this is not the case. Therefore presumably the house was not in your name, and you had purchased in some one else's name - or it was a lease.
2. I have no trouble remitting funds to the UK but I can prove where my funds come from, and I have not had to send a large amount that goes above Thai export controls, but it is always gets checked where it comes from.
3. The Thai Bank were not satisfied and so you took it out in cash and "smuggled" it into the UK unbeknown to the Thai authorities.......
Can you please tell me why this is not money laundering? You say it is your money, but why did you have problems in Thailand, something does not make sense!