Love Blues

Hi guys, this is my first ever attempt, in producing a classical, orchestral piece. It's a theme for the blues in love. So, pls do let me know your opinions, and also, pls suggest what I can further add on to, in the transition sec (3.45th min), since I think it was kinda abrupt. Anyways, please do listen, and, cheers!

Fixing the 3:45 is easy. Just remove everything from 3:40 to 3:50. I believe 3:40 joins into 3:50 nicely.

However...the reason why this joins so nicely is because you don't have any key changing going on here. This style may work in pop or other genres but definitely not in classical, for the very reasons that there are no vocals or drum beats. If you don't ever change key, the ear quickly becomes desensitized. You also repeat a lot of your ideas over and over again, so you can easily fix this by cutting this piece from 4 minutes to just a minute and a half. No need to have this go on for 4 minutes.

What type of music are you used to composing btw?

Basically it's the same variation of the falling fourth motive [C-Bb-Ab-G] and [F-Eb-Db-C], and the chord progression is almost the same throughout the piece. Classical pieces featuring this kind of structure would be ground or chaconne, but at least the melody will change and new elements will be added on top of the repetitive melodic/harmonic ostinato. There is some instrumental change during each reappearance of the thematic cycle, but that may not be enough to create contrast for listeners to enjoy it. 

Many elements can be added on. For example, on top of the falling motive modulating to the relative major Ab major will be great. If it's a sad love, there should be something sweet and regrettable in it, not just lamentation in f minor. Contrasting theme can be added, dynamics and rhythms can vary much more than here.

For the issue in 3:45, I think a simple dominant chord will join the passages easily, with the reason @chopin suggested.

But that's your first attempt in composing an orchestral piece. That's a good start!