I'm European and I moved to France with my French BF for the same reason, love. I stayed there 9 years. I wouldn't recommend it for you at all. Here's why, in part (some of it comes from a response to a different post that I made). If you want more info, feel free to DM me.

-Your potential partner is doing you a disservice, expecting you to easily fit into the French system and learn French fluently very quickly. I learnt it fluently only to have them be very rude and ignorant because I had an accent. I had to learn to write it well also because my partner said he didn't understand the regulations or laws, turned out he became a Union rep after I keft him, that's basically all regulations and laws. He couldn't be bothered. Are you sure this man will do all he can to support you because you will be totally reliant on him?

• salaries are lower and taxes higher than other EU countries. As a result public services are better but you pay for them.
• French people come first when it comes to jobs and it's difficult to find professional employment as the French stubbornly believe that degrees from other countries are inferior, although that seems to be an excuse to exclude foreign people from many jobs. In Iothwr EU countriea,, we embrace foreign nationals and treat them equally, something we cannot expect in return I'm France.
• half the country works for the civil service which is totally corrupt and they ignore European law and your rights, basically doing what they want. They have no problem lying to your face and will do so with a smile. In fact, lying seems to be so prevalent that every piece of correspondence from the government is sent by registered letter, otherwise the French pretend they didn't get it.
• as a Thai national you can expect even worse treatment and you will be required to pay for certified translations of all your documentation and if you drive they will not recognize your driving licence and you will be required to start again.
• you have to fight for your rights as they are automatically denied in many cases, even for EU nationals.
• there are so many laws, constantly quoted in all correspondence and the news, that it's hard to keep track of them and, unlike other EU countries, the French system legislates for everything( because they have to provide something for all the civil servants to do).
• if you run a small business the French government estimate what they think you should pay in tax and you have to pay it, then sort it out later if you can. There are lot's of stories about the RSI putting companies out of business with outrageous demands for tax that's simply estimated, a guess plucked from thin air. If you're self employed you have to pay social charges and taxes even if your revenue is zero in many cases.
• It's difficult to succeed in politics if you didn't go to the elite Sorbonne University or the Ecole D'administration (yes, a university for the civil service) and French politicians tend to be very rich(whether or not they're landlords) like Segolene Royal, Macron etc or they have a cosy relationship with very rich people, as with Sarkozy and Madame Bettancourt (the heiress of L'Oreal and richest woman in France and 14th in the world at one point.) Then there's the far right and their relationship with Russia and Russian money.
• the French strike all of the time and protests are frequent but they rarely achieve very much. That's why the far right candidate always makes it to the presidential run-off, as a way to scare the incumbent government. But, be under no illusions, the far right sentiment is very prevalent and it's not a welcoming one for many ethnic minorities and there is rampant mysogyny and homophobia. France has a lot to sort out and the situation regarding the far right and a potential FREXIT situation is far from resolved. -Oh, and if you speak English, they automatically assume you're British whom they hate. Not many will make an effort to speak English with you, although nearly everyone in France lies and puts English on their CV.
• don't expect to find work until you have fluent French and you will have difficulty getting medical cover (Carte Vitale) because you've no social security and aren't an EU citizen. Have you discussed any of this with your partner?

I could go on as there's more. France is far from perfect and I think you'd be crazy to move there and quit your job for a man who won't do the same for you. The French are very selfish people and all of the websites about moving to France are very rose tinted. It's OK if you're retired or have business across EU countries but don't expect it to be in any way easy. Relationships don't last always and you'd need to be very sure about it. Is he offering to marry you, does he have kids (they'll get his inheritance), are you happy being at home and a husband was hole he works? Is there a Thai community because that's likely where you'll find work. Will you like winter in Lyon? Brrr